Only hours before, bursts of gunfire echoed through the streets - likely from armed police - and at least three blasts rang out as officers performed controlled explosions after sweeping the area for possible bombs.
"They went "this is for Allah" and they had a woman on the floor, they were stabbing her", said witness Gerard Vowls.
London's Metropolitan Police said armed officers fatally shot the attackers within eight minutes.
One woman was taken away on a stretcher while others sat injured on the ground, with shocked people crying and shouting around them.
As emergency services sped toward London Bridge, reports came in of multiple stabbings nearby, in the area around Borough Market, a popular gourmet food market surrounded by fashionable bars and restaurants. The prime minister also said that the government would review its existing counter-terrorism strategy and look at increasing sentences for terror offences.
He said: "I could see on my left a further individual was having CPR performed on them by the emergency services". "Our thoughts are with those who are caught up in these awful events".
On Saturday, Conservative leader Andrew Scheer tweeted that he was "horrified by the events in London" and that Canada would always stand with the people of London.
He urged all Londoners to "remain calm and vigilant today and over the days ahead".
"Now the area is completely closed with police cars going one way and ambulances going the other", he told Reuters.
Somehow Ms Hedge's attacker's blade missed her major arteries and windpipe, leaving her with a non-life threatening injury.
The social network was not just used by people to let loved ones know that they were safe following the attacks, but also to share footage of the shocking aftermath. The Sun reported that three men with "hunting knives" jumped out of vehicles and starting stabbing people.
The ambulance service said almost 50 victims were rushed to five hospitals with injuries from the attack, including one police officer who was one of the first responders on the scene.
Hedge was in a restaurant with her boyfriend after finishing work for the night when she was stabbed in the neck by one of the offenders.
"Searches of a number of addresses in Barking are continuing", London's Metropolitan Police said in a statement.
After the white van crashed into fencing by Southwark Cathedral, knifemen sprinted towards nearby bars packed with revellers enjoying a Saturday night out. Within minutes, the three were shot dead by police.
It is the third terror attack in the United Kingdom in three months, following the auto and knife attack in Westminster in March, which left five people dead, and the Manchester bombing less than two weeks ago, in which 22 people were killed.