London: "This is not a joke" the police officers yelled, waving to my right. "Run, quickly, move, get out, go." 

Park Street approaching Borough Market was unusually and eerily empty. The market, a frequent backdrop in the Bridget Jones movies and now "too posh" as one Black Cabbie once described it, is filled with gourmet burger stands, cheese stalls, hip eateries, fishmongers, trendy pubs and organic grocers galore and always insufferably packed on weekends and even more so on a warm night, as it was on Saturday. 

At least 100 people were locked in the basement of the Old Thameside Inn overlooking the river under police watch, as they worked to find a safe evacuation route, either by boat across the river, or by foot. 

Dozens poured out from the market and London Bridge area to more equally forceful police. "Run, leave, go," they yelled, lining Southwark Street.  Ambulance and police cars concealed the old bricked railway arches.

"Those people, I can't look," a young girl running alongside whispered aloud through tears. Across the road on the footpath were several people being treated by ambulance officers.

Dozens of police cars screamed up the street drawing to a halt beneath The Shard - lit flickering blue at the base, a blunt contrast to the warm gold tip that lights the London skyline.

Armed police were seen running across the road and four loud muffled bangs were later heard. Another four loud bangs rang out, competing with the urgency of the helicopters raging above, as police carried out controlled explosions on London Bridge, closed to all traffic.

The most dramatic scene came when the 100 or so people who had been in lockdown in the Old Thameside Inn's basement, ran down Southwark Street together with their hands above their heads. 

"We've been in a basement," a young Australian male, escorting two women said, as he kept running.  Many were in tears. "No photos of me please," said one middle-aged man shielding his face as he ran through the swelling media contingent. 

Steph and Cath, two girls in their 20s were stuck on the footpath at 12.30am, unsuccessfully trying to hail an Uber after their plan to catch the train home from London Bridge station to Tonbridge Wells, in the picturesque home county of Kent, was derailed. 

"We were rushed into a pub by someone who worked in Borough Market, he's like 'get into this pub,'" said Steph. "The people around us heard gunshots."

"We down there [in the basement] for an hour," said Cath.

"Then we got escorted out women and children first. We were supposed to go across the river but they couldn't get us on boats, there were too many of us, a hundred at least" said Cath.

Both girls were clearly shaken by their ordeal and Cath was emotional but defiant.

"You know it's going to happen with the current climate we're in," she said.

"Ultimately, I'm sorry, but f--- them. Everyone was together, we all clubbed together," she said.

Three restaurant workers at Porteña, an Argentinian street food vendor nestled in Borough Market recounted seeing the three attackers stabbing people at random.

"People crazy, with a knife," Patrick said.

Alex Martinez works at the taco vender El Pastór, across from Porteña as a waiter. He hid in a bin for an hour when he saw one of the men enter the restaurant with a knife.

"I was working behind the bar and one man entered my restaurant." 

He knew it was terrorism "straight away" by the way he was shouting and smashing plates onto the floor. He didn't wait to see any carnage. He fled out the back and shut himself in a giant container bin. "I tried to be safe." 

Although he could not see he could still hear the screams and then the shots, as police killed the attackers, eight minutes after they began their murder on London Bridge.

By 1am the streets dwindled to police, and overhead the media cordon hung a leftover sign warning of restricted access to Borough Market because of the funeral procession of PC Keith Palmer, the officer stabbed to death by Khalid Masood in Westminster in March. 

Three months later the same roads would be closed for another grim purpose.

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