The number of protesters who marched in the streets Wednesday was the largest seen in Yangon since the military coup over two weeks ago.

The crowds were at their largest around lunchtime local time, and various activists and elected NLD politicians gave speeches condemning the military takeover. There have been no reports of violence so far.

Images from the city showed peaceful protesters marching and carrying banners reading "Release our leader" and "Join CDM" the civil disobedience movement. Others blocked roads and bridges with cars, leaving their engine hoods up as if they had broken down.

The crowd in Yangon was joined by young people, striking factory workers, teachers wearing red ribbons on their shirts, monks and members of the LGBTQ community waving rainbow flags. Large posters were unfurled over walkways with some depicting the three-fingered salute from the "Hunger Games" franchise that has become a popular symbol of protest in Myanmar and neighbouring Thailand.

The United Nations special rapporteur on human rights in Myanmar, Tom Andrews, said he was "terrified" of the potential for violence if the planned mass protests and military troops converge.

"I fear that Wednesday has the potential for violence on a greater scale in Myanmar than we have seen since the illegal takeover of the government on February 1," said Andrews.

Andrews said he had received reports of soldiers being transported into Yangon from outlying regions.

"In the past, such troop movements preceded killings, disappearances, and detentions on a mass scale," he said. "We could be on the precipice of the military committing even greater crimes against the people of Myanmar."

Soldiers from the Myanmar military's light infantry divisions (LIDs) -- long documented to be engaged in human rights abuses -- have been seen in the country's largest city, Yangon, in the past week.

These elite counter-insurgency forces come under direct orders from Myanmar military's commander-in-chief, Min Aung Hlaing, and they have been accused of human rights violations, carrying out violent campaigns against ethnic minority armed groups and civilians, and have a history of brutally crushing protests.

Conflict-ready infantry troops trained to fight ethnic rebels in the jungles and mountains and who now appear armed on city streets is cause for worry, analysts say.

"These light infantry divisions, these are the ones to be concerned about," said Human Rights Watch researcher on crisis and conflict Richard Weir. "These are the kinds of units that can be deployed very quickly to city streets."

Weir described the LIDs as an "expeditionary force that goes out when other units aren't able to handle a certain situation."

It is unclear how big of a presence these soldiers have in Yangon. So far clashes between security forces and protesters have been isolated skirmishes.

Brutal history

The international rights group said the 77th LID was "deeply implicated in many of the violent incidents and killings documented" and was "actively engaged in the violent suppression of demonstrations."

Analysts say one reason for the deployment of these frontline combat units could be that they are easily transportable and often move around the country. But also that their presence sends a message.

"The LIDs have a very nasty reputation and I think that at the very least, people will recognize and have recognized their presence," Weir said. "The increased military presence period is clearly something that's meant to demonstrate resolve, and to intimidate. This is not something we saw on the first week after the coup."

The Myanmar military, known as the Tatmadaw, is also fighting some of the world's longest civil wars in the ethic states against rebel armed groups. Tatmadaw troops have long been documented by various human rights groups of repeated abuses such as using rape as a weapon of war, and other forms of sexual violence, extrajudicial killings, torture, forced labor and conscription against civilians.

Mass protests

Since the coup, hundreds of thousands of people have protested or carried our civil disobedience campaigns in major cities across Myanmar, calling for generals to give back power to Suu Kyi and her party, the National League for Democracy (NLD). The NLD claimed an overwhelming victory in elections in November, taking 83% of the vote, which granted it another five years in government, but the military alleged widespread voter fraud and used this to justify seizing power.

Yangon residents have reported a palpable fear for their safety after dark, with many scared they will be dragged out of their houses by police in nighttime raids, or are terrified of reports of arson and crime following the release of thousands of prisoners in an amnesty last Friday. Widespread internet shutdowns at night have heightened the fear.

One journalist in Yangon, who wanted to remain anonymous for fear of arrest, said rights defenders and reporters are struggling to let the people know what is happening.

"Journalists are in remote working and in hiding as they are scared of night arrests and their homes going to be raided. They can be arrested anytime for what they are reporting although (it's the) truth," the reporter said.

Hundreds of people have been arrested since the coup, and most held without charge, according to the United Nations human rights office. The Assistance Association for Political Prisoners Burma (AAPPB) said at least 452 people have been detained in relation to the coup.

"There is a systematic move right now to just scare the living daylights out of people. First of all, you've got to remember, put this in context, this is a very brutal military, and it shows no reservations whatsoever of massacring protesters protesting for democracy in the past," said UN rapporteur Andrews.

By day, protesters -- many of them young people -- remain defiant.

Activist Myo Htet, who could be seen with a microphone rallying crowds at a protest last week, said demonstrators were fighting for their future.

"We are not fighting for one leader, we are fighting for the country, we are fighting for our future, we are fighting for our next generation," he said. "No matter how nasty they are, no matter how they gunshot, the tanks are powerful, at the end of the day, I believe that we people are the most powerful. If we unite."

Myanmar had suffered under half a century of isolationist military rule with a series of martial dictators who enforced their will through fear and brutality. In 2011, the military chiefs put in place a plan that would permit the country to hold elections, liberalize the economy, and transition into a semi-democracy while still maintaining their authority. It paved the way for Suu Kyi to be elected in 2015.

But the trauma of military rule is still carried by many in the country.

"Throughout my life, I grew up in the dark era, we were so afraid of everything. We've grown up in the military junta, and I cannot pass that kind of terrible experience to my next generation," said Myo Htet.

"We're fighting to get rid of the military dictatorship from Myanmar once and for all, this is our fight. Yeah, we are fighting for that."