The incident bore similarities to a March attack on Westminster Bridge, west of London Bridge, in which a man killed five people after driving into a crowd of pedestrians before stabbing a police officer in the grounds of parliament.
Responding to the London incidents, US President Donald Trump sent out a series of tweets assured the British people that his country will do whatever to help the people in London. And that's what we know so far from London Bridge.
The Metropolitan Police tweeted, advising people to "run, hide and tell".
It was not clear if the incidents were related and the situation did not appear to be fully in control.
In a statement issued last night, Prime Minister Theresa May said, "The awful incident in London is being treated as a potential act of terrorism".
Six civilians were killed and dozens more were injured before three attackers were killed by police in London.
Armed police also responded to reports of stabbings and shots fired at the nearby renowned Borough Market, as well as to the unrelated stabbing in the Vauxhall district. Three terrorists then came out of the van and stabbed a number of people in Borough Market at around 22:00 BST.More news: Bernie Sanders slams Trump during visit in Berlin
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"The suspects were wearing what looked like explosive vests but these were later established to be hoaxes", Britain's head of counter-terrorism Mark Rowley said.
Chris Jacobs, 52, and his wife Kavita Jacobs, 49, were woken up by police officers banging on their door on the third floor of an apartment building at Borough Market.
Someone sprinted through the doors with a dire warning: "There is a man with a knife up there, and he's coming this way".
A man with a massive knife charged into the restaurant, Smedley said.
As thousands of people flooded from the area of the attacks - many unable to get home with nearby subway stations shut - locals were quick to offer assistance. One was a waitress who had been hiding behind a partition.
"Around the corner, there was a guy with a stab wound on his neck".
While stabbing civilians, the men shouted: "This is for Allah". "TELL - the police by calling 999 when it is safe to do so". This will relieve pressure on Casualty Bureau.
British Prime Minister Theresa May will convene an emergency security Cabinet meet known as Cabinet Office Briefing Room (Cobra) after terror attacks took place at the London Bridge and the Borough Market, where several people were injured.
The officer is being treated in a central London hospital and his family have been informed and are with him.