• Metropolitan Police said the vehicle hit pedestrians on the bridge at 10:08 p.m. (5:08 p.m. ET).
• “Armed officers responded and shots have been fired” in Borough Market, police tweeted. There were no further details about the gunshots.
• British Prime Minister Theresa May said the “terrible incident in London is being treated as a potential act of terrorism,” according to a statement.
• The Prime Minister will chair a meeting of the Government’s Cobra emergency committee — her top security advisers — Sunday.
• US President Donald Trump has been briefed by the national security team, White House Press Secretary Sean Spicer said. Trump tweeted: “Whatever the United States can do to help out in London and the U. K., we will be there – WE ARE WITH YOU. GOD BLESS!
• London’s Metropolitan Police said a separate incident in the Vauxhall area of London was not connected to the events on the bridge and at the market.
A witness on the bridge told CNN the van mowed down pedestrians as it sped south across the bridge, leaving bodies lying in the roadway.
Another witness, who was in the cafe, said a man with a “massive knife” entered the restaurant at Borough Market, just south of the bridge, and stabbed two people inside. The patrons sheltered in the basement and police then arrived at the scene, the witness said. The condition of the stabbed people was not known.
Mark Roberts, the witness on the bridge, said the van was traveling south across the River Thames at a high rate of speed and was swerving as it struck several people, knocking one person “about 20 feet into the air.”
The van swerved into oncoming lanes before hitting a bus stop and coming to a stop, Roberts said.
“Within my line of sight, there were five or six people on the ground that were not moving,” he said. “It looked to me that the van was aiming at the people.”
Roberts said he heard what sounded like gunshots about 10 minutes later. He estimated 100 people were on the bridge at the time, fewer than earlier in the night because it was getting late.
“I froze, to be honest,” Roberts said. “As I was thinking … which direction should I run, the van swerved across the other side of the bridge from me.”
The cafe stabbing occurred in Borough Market, a popular market with gourmet food and produce stalls and several restaurants inside.
A witness said they were in the front of Elliot’s Cafe when a large group of people started running up the street from Borough Market.
“Someone said, ‘What is going on?’ and one of the people running said, ‘There is a man with a knife up there and he is coming this way.’ There was complete panic as everyone ran to the back of the restaurant and crouched down trying to hide themselves from view,” the witness said.
“A man suddenly appeared in the restaurant with a massive knife — some people in the restaurant believe there may have been another man — but it was so chaotic it was hard to tell,” the witness said.
The man with the knife stabbed a waitress, who was hiding behind a partition, in the neck and stabbed a man in the back before running out of the restaurant, the witness said.
Police activity spread throughout the Borough Market area. Officers rushed into Katzenjammers bar and ordered people to sit on the floor, patron Paul Connell told CNN.
“The police were absolutely brilliant, they came in and explained the situation,” he said. ” Armed police came in. They told us to remain on the floor but to stay calm. We were eventually led out of the bar and some kind people working in a hotel let us come in to use the bathroom and to give us water.”
The US embassy in London tweeted: “Please avoid the area and monitor local news/@metpoliceuk for updates.”
At 11:44 p.m., Metropolitan Police tweeted that officers were also responding to reports of an “incident” in the Vauxhall area, about 2.5 miles southwest of Borough Market, also on the south side of the Thames.
London Bridge Tube station was closed and London Bridge was closed in both directions.
Saturday’s incidents also come more than two months after a man drove an SUV into a crowd on the sidewalk along Westminster Bridge in London, killing at least four people.
After ramming the car into a barrier outside the Houses of Parliament, the driver got out and stabbed a police officer to death. The attacker was gunned down by a police officer.
The assailant, Khalid Masood, 52, of West Midlands, reportedly had a criminal record and may have had connections to violent extremism, British Prime Minister Theresa May said.
CNN’s Alex Felton in London contributed to this report.