A senior rebel leader and several protesters, whom CNN is not identifying for security reasons, say a small, but growing number of pro-democracy activists are heading into the jungles where they are receiving combat training from ethnic militias.

There are also increasing calls from the urban centers for the ethnic rebel groups to do more to protect people from the military violence.

A protest group formed by some of the myriad ethnic minorities in the country recently called on 16 ethnic armed organizations to "urgently" protect the lives of the people.

And last Tuesday, three rebel groups in the north of the country, which call themselves the Three Brotherhood Alliance, said if the Myanmar military does not stop killing civilians, "we will join the spring revolution with all the ethnicities for self defense actions."

If the military "continues to shoot and kill people, it means the junta have simply transformed themselves into terrorists," Yawd Serk said. "We won't just sit still, we will find every means to protect the people."

Myanmar's military junta has repeatedly blamed the violence on protesters and said security forces were using "minimum force." Military spokesman Major General Zaw Min Tun said during an interview that junta forces cracked down because "the crowd are blocking with sand bags, shooting with handmade guns, throwing with fire, throwing with molotov and the security forces have to use the weapons for the riot."

He also said the junta "will hold a free and fair election after the state of emergency," which is in place for one year.

Airstrikes and refugees

The Tatmadaw is a highly trained fighting force that ruled the country for more than half a century through brutality and fear, turning Myanmar into a poverty-stricken pariah nation.

In the cities, elite counter-insurgency troops involved in these atrocities have been deployed and seen armed on the streets alongside other security forces.

The Tatmadaw bombs have killed at least six civilians, including children, and sent 12,000 people running from their homes, humanitarian groups said. Some of those villagers fled over Salween River into neighboring Thailand.

The offensive came after a KNU brigade seized a military base in Mutraw district. In retaliation, Myanmar military ground troops have now advanced into the rebel territories "from all fronts," the KNU said.

In the country's north, fighting has also increased since the coup between Kachin rebels called the Kachin Independence Army and the military, displacing hundreds of people, according to local media.

Both the KNU and RCSS are signatories of a 2015 Nationwide Ceasefire Agreement (NCA), signed by 10 ethnic armed organizations. The two groups have signaled the attacks mean the uneasy ceasefire deal was now at risk.

"We have long foreseen a military offensive at the end of the dead-end NCA peace process," the KNU said. Its head of foreign affairs, Saw Taw Nee, said the agreement was "paralyzed."

Shan leader Yawd Serk said that since the coup, "all things on the negotiation table just collapsed."

Analysts say the military will be keen to avoid a situation in which it is drawn into conflict with multiple groups at once.

"Ultimately, the priority for the Tatmadaw is always going to be the heartland and maintaining control of the central government," said Matthew Henman, associate director and head of Jane's Terrorism and Insurgency Centre. He added that while many of these groups can't compare to the size and firepower of the military, they "could prove to be a real kind of destabilizing force."

Last week, Myanmar's military junta announced on state television a unilateral ceasefire for one month, which appeared to refer to military actions taken against ethnic armed groups, which it called on to "keep the peace." Excluded from the peace, however, are those who "disrupt" government security.

Fleeing protesters in ethnic areas

Fleeing the killings, beatings, arbitrary detentions and midnight raids in cities across the country, a growing number of people are seeking shelter in some of these ethnic areas controlled by rebel insurgents.

Saw Taw Nee said about 2,000 people had fled the junta's crackdowns in towns and cities to KNU territory, among them protesters, striking workers with the Civil Disobedience Movement, ousted government officials, and members of Aung San Suu Kyi's party the National League for Democracy. The KNU said it was providing them with humanitarian assistance such as food and shelter.

"Mostly they involved in the movement and they dare not to stay any longer in their place and they are being sought for arrest," Saw Taw Nee said. "Most are very young people."

Saw Taw Nee said he supports the protesters in cities by giving advice over video platforms on how to survive against the military's guns on the streets.

"We support them not by going into the cities with a big army," he said.

Shan leader Yawd Serk said they are also giving protection to those fleeing the junta.

"If we enter the cities we will inevitably justify the acts of the Burmese junta. We are not entering cities. People who flee, we will take care of them. They are protesting peacefully," he said.

Jungle training camps and calls for armed resistance

Not all protesters are only seeking sanctuary, however. A small percentage are now also heading to the jungles with the intention of learning how to fight back.

At least 570 people have been killed by security forces since the coup, according to advocacy group the Assistance Association for Political Prisoners. Among them are 46 children, the United Nations Children's Fund UNICEF said. Protesters have tried to defend themselves against the security force's bullets with flimsy homemade shields, plastic hard hats and barricades made of sand bags.

But as the death toll continues to rise, one protest leader in Yangon said the movement is fracturing. Alongside the mass peaceful protests across the country, a small radical fringe is emerging.

The Yangon protest leader, who did not want to be named for his safety, said some demonstrators in the city have made largely unsuccessful attempts to carry out what they call "carwash operations."

"A carwash operation is throwing molotovs at a moving or stationary vehicle. Whether there is army personnel in it or an empty truck," he said. Another was a "cleaning service," which he said refers to arson attacks.

It is unclear how widespread or accepted the two actions are among the protest movement in Yangon, and the protest leader did not point to specific occurrences. While he is against violence, he said, other protest leaders are encouraging this type of operation. And as the situation deteriorates in the cities with increasing deaths, arrests and enforced disappearances, more people, the protester leader said, could be swayed to take action.

"When ordinary civilians like us, office workers like us, start taking arms and get training for six months and start shooting people, I guess civil war would be unavoidable," he said. But increased violence, he added, "won't accomplish our goal" and would only play into the junta's hands.

"Actually that kind of movement would drive us farther away from our goal of getting rid of this dictator," he said, referring to junta chief Min Aung Hlaing.

Peaceful pro-democracy demonstrations in 1988 were brutally put down by the military. Thousands were killed -- and the thousands more arrested were given decades-long prison sentences and subjected to torture. Young protesters formed a student army called the All Burma Students' Democratic Front to fight against the junta and trained under some of the rebel groups.

Now, some activists are following a similar path.

One protester CNN spoke to, who did not want to be named for safety reasons, said he had been receiving training at a jungle camp for the past three weeks.

It is unclear precisely how many people were at the camp, but the activist said those training alongside him were "very ordinary people" who felt they had no other choice. They were now learning how to use guns and build bombs, the activist said.

"They (the security forces) just shoot us. We don't have anything. We just walk on street with nothing in our hand and then they shoot us," he said. "It should be weapon and weapon, it should not be non-violence and then weapon. It became no choice for us."

The senior rebel leader, whom CNN is not naming for security reasons, confirmed a few dozen protesters were receiving military training in his territory.

"They have learned just like how we trained our soldiers," the rebel leader said. "They said they have nothing to lose, they have to finish this military dictatorship otherwise there is no future for Myanmar."

Back in Chiang Mai province, Shan leader Yawd Serk held his cards close to his chest about what role his rebel group will have if the military violence continues, but said they will support the protesters -- including training them.

"When they flee from trouble, we will take care of them. But if they want to have training, we will train them," he said. But he added, "We have to separate peaceful protest. If we end up sending protesters with weapons it would just justify the killing of Burmese military."

After more than 70 years of conflict, Myanmar is awash with weapons that can be bought on the black market, though there's no evidence that they're being stockpiled in the cities.

The military junta announced in state controlled media Friday citizens who have fled to the ethnic areas or overseas would be allowed to return.

"The State Administration Council will arrange their returns from evaded areas to various regions of Myanmar," the military said. However, the invitation exempts "persons who committed any kinds of crime," a vague directive that could be applied to anyone.

What comes next

Meanwhile, a group of ousted lawmakers with the ruling NLD are spearheading calls to form a federal army that includes the ethnic armed groups. They have also revealed plans to form a transitional government to counter the military junta themselves.

The group, called the Committee Representing Pyidaungsu Hluttaw (CRPH) appears to have widespread support among the leaderless movement, and released last week an interim government roadmap that, among other things, calls for escalating the country's civil disobedience movement.

"The CRPH is going to form a government in the very near future. And the government will have its own army. We have been talking to ethnic armed groups and we have the right to defend ourselves. The people have the right to defend ourselves," said Htin Lin Aung, the CRPH's representative of international relations based in Maryland, US.

But uniting the disparate rebel groups against the Tatmadaw is unlikely and several rebel leaders say such a movement is a long way off becoming a reality. While many have formed alliances, there are deep rooted differences and continued inter-fighting between others. There is also a strong distrust among ethnic minority people that any Bamar majority governance group, like the CRPH, would be serious about incorporating the ethnic wishes of federalism and self-determination from the start.

The KNU's Saw Taw Nee said it was important first to build a federal democratic union, in which all ethnic groups are represented, then a federal army could follow.

"Its very difficult to have an army like this now. Mainly because we have different opinions, different backgrounds, among ethnic groups," he said. "The main thing is to build trust between ethnic people."

The RCSS's Yawd Serk said it was "not the right time to talk about our military capacity." But he did say "we have been in war for decades, we know what we need and how much we need. And we have already prepared for that."