London (CNN) British police identified the man suspected of killing two people in a terrorist attack near London Bridge on Friday as 28-year-old Usman Khan.

Khan was convicted in 2012 for terrorism offenses and had been living in the Staffordshire area after he was released from prison last year with an ankle monitor, Metropolitan Police Assistant Commissioner Neil Basu said in a statement.

Police say Usman Khan, 28, is the suspect in Friday's attack in London.

Basu said authorities are not "actively seeking anyone else in relation to the attack."

Police officers shot and killed Khan after two people were stabbed to death, and at least three others were injured during the attack on Friday, London Metropolitan Police said. The suspect had a fake bomb strapped to him when he was shot, police said.

Speaking before a meeting of the UK government's emergency response committee Cobra on Friday night, British Prime Minister Boris Johnson said it was important to enforce appropriate prison sentences for criminals.

"I have long argued that it is a mistake to allow serious and violent criminal to come out of prison early, and it is very important that we get out of that habit, and that we enforce the appropriate sentences for dangerous criminals, especially terrorists," he said in a pool interview.

Photos: Stabbing incident at London Bridge Floral tributes near London Bridge on Saturday, November 30. Hide Caption 1 of 21 Photos: Stabbing incident at London Bridge Forensic officers examine the river Thames bank under London Bridge. Hide Caption 2 of 21 Photos: Stabbing incident at London Bridge The Union Flag flies at half mast on the Victoria Tower in London. Hide Caption 3 of 21 Photos: Stabbing incident at London Bridge Police and emergency services work at the scene of the terrorist near London Bridge on Friday, November 29. Hide Caption 4 of 21 Photos: Stabbing incident at London Bridge Police search a person near London Bridge on November 29. Hide Caption 5 of 21 Photos: Stabbing incident at London Bridge Police evacuate the Borough Market near London Bridge. Hide Caption 6 of 21 Photos: Stabbing incident at London Bridge Empty buses are seen parked on London Bridge. Hide Caption 7 of 21 Photos: Stabbing incident at London Bridge Office workers watch from windows as the police carry out an operation following the terrorist attack. Hide Caption 8 of 21 Photos: Stabbing incident at London Bridge A police officer and dog work near Borough Market. Hide Caption 9 of 21 Photos: Stabbing incident at London Bridge Police evacuate Borough Market. Hide Caption 10 of 21 Photos: Stabbing incident at London Bridge A police officer runs along a street after reports of shots being fired. Hide Caption 11 of 21 Photos: Stabbing incident at London Bridge Staff members are ushered into a Fitness First gym after reports of shots being fired. Hide Caption 12 of 21 Photos: Stabbing incident at London Bridge People rush away from Borough Market after police told them to leave the area. Hide Caption 13 of 21 Photos: Stabbing incident at London Bridge Traffic is stopped near Borough Market. Hide Caption 14 of 21 Photos: Stabbing incident at London Bridge A police officer cordons off the London Bridge Station. Hide Caption 15 of 21 Photos: Stabbing incident at London Bridge A woman runs from the London Bridge area. Hide Caption 16 of 21 Photos: Stabbing incident at London Bridge Police gather near Borough Market. Hide Caption 17 of 21 Photos: Stabbing incident at London Bridge Members of the public are held behind a police cordon near London Bridge Station. Hide Caption 18 of 21 Photos: Stabbing incident at London Bridge People stand outside the London Bridge Station after it was closed. Hide Caption 19 of 21 Photos: Stabbing incident at London Bridge Police help direct people at the scene of the attack. Hide Caption 20 of 21 Photos: Stabbing incident at London Bridge An ambulance makes its way to the scene of the attack. Hide Caption 21 of 21

British authorities were searching a property believed to be linked with the suspect late Friday, a law enforcement source told CNN.

2 people killed, 3 others hurt

The rampage began just before 2 p.m. at Fishmonger's Hall, a historic building on the north side of the London Bridge. The suspect was attending an event in the building organized by the University of Cambridge's Institute of Criminology, according to the assistant commissioner and the organizer's website.

"We believe that the attack began inside before he left the building and proceeded onto London Bridge, where he was detained and subsequently confronted and shot by armed officers," Basu said.

Video filmed by a bystander shows a man being wrestled to the ground by several bystanders on the northern end of the bridge, shortly after police were called to Fishmonger's Hall.

Tom Gray, a tour guide who tried to apprehend the suspect, told CNN affiliate ITV that the attacker was "wielding two knives, one was duct taped to his hand." After other bystanders had held the suspect down, Gray said he tried to "stamp the other knife from his wrist" and then kicked it further down the bridge.

Lloyd Griffiths, 35, who was on a bus on the bridge, said he saw the attacker had a large blade.

"I saw a shine on a knife or metal blade, it was startling. It was large blade, it wasn't small, and then I was locked on the bus, people tried to tackle to man trying to fight him, ordinary people jumping out of the car, trying to fight him," Griffiths said.

London Bridge timeline 1:58 p.m. (8:58 a.m. ET): Police called to a stabbing at premises near London Bridge.

2:36 p.m. (9:36 a.m. ET): British Transport Police declare London Bridge closed.

2:46 p.m. (9:46 a.m. ET): London Ambulance Service declares "major incident."

2:47 p.m. (9:47 a.m. ET): National Rail says no trains will call at London Bridge station until approximately 5 p.m. (10 a.m. ET).

3:55 p.m. (10:55 a.m. ET): Metropolitan Police say a number of people have been stabbed.

4:24 p.m. (11:24 a.m. ET): Metropolitan Police Assistant Commissioner declares it "a terrorist incident."

"Then police ran over with guns, screaming," before shooting the man, Griffiths added. Multiple emergency vehicles quickly arrived on the scene as crowds of people fled the area.

A man and woman were killed in the attack on Friday, Basu said in a statement early on Saturday. Three others, a man and two women, were injured and remained hospitalized. None of the victims have been named.

Authorities have not discussed the motive for the attack but earlier on Friday, Basu said it had been declared as a terrorist incident.

"I must stress, however, that we retain an open mind as to any motive. It would not be appropriate to speculate further at this time," Basu told reporters Friday afternoon.

In the wake of the attack, Metropolitan Police Commissioner Cressida Dick said officials decided to enhance patrols, including armed and unarmed officers, in the area and across the city and are encouraging residents to cooperate with police.

"Fighting terrorism takes effort and determination from all of us. If you have any information or concerns, please do contact us," Dick said. "The empty ideology of terror offers nothing but hatred and today I urge everyone to reject that. Ours is a great city because we embrace each other's differences, we must emerge strong and still from this tragedy."

The incident comes more than two years after eight people were killed and dozens more wounded in a terror attack at London Bridge.

London mayor Sadiq Khan praised the "breathtaking heroism" of "ordinary Londoners" who risked their lives to intervene in the incident. "We are resolute, we stand united in the face of terrorism and we will not allow anybody to divide us," Khan said in a press conference.

President Donald Trump has been briefed on the incident and is monitoring the situation, Deputy White House Press Secretary Judd Deere said in a statement.

Scenes of panic at a busy London hub

Witnesses described scenes of panic as swarms of Londoners were rushed away from the bridge by police, while major buildings surrounding the area including the Shard skyscraper were put on lockdown.

Simon Shorey was eating with his family in a burger restaurant when the incident occurred. "The whole restaurant had people under their tables and sat down on the floor," he told CNN. He says people were trying to keep updated with the latest developments on their phones and the atmosphere started to calm down.

Office workers peer out of the windows of Leadenhall Market near London Bridge.

"There were people running down the street just outside the windows of the restaurant. They weren't screaming at that time, but people were running back down and after a few more minutes we were told 'everyone out, everyone out.'"

Olivia Bizot, who was present at the Boston marathon bombing in 2013, added: "I was coming towards the bridge on my bike and I heard explosions. I didn't really assume it was gunshots at first."

"All of sudden all these people came running like a flood of people ... A few years ago, I was at the Boston marathon bombings and I was at the finish line just before it occurred and it was the same thing — everyone running, panic on their faces," she added.

Armed police near Borough Market.

A white lorry was seen stationary across multiple lanes of traffic in the middle of the bridge, which armed police approached after the incident. It was unclear whether the vehicle is related to the attack.

Other videos from the scene showed people evacuating pubs near the bridge. London Bridge is a busy area of the city which houses several restaurants, bars and businesses and is near Borough Market. It was also Black Friday, one of the busiest shopping days of the year.

Jinnat Ui Hasan told CNN he was in a meeting in a building near the incident when he heard "more than five" gunshots.

Elsewhere, Stevie Beer, 26, told CNN that her place of work which overlooks the bridge was in lockdown Friday afternoon.

Gunshots heard on London Bridge. Huge amount of police. pic.twitter.com/U6Qo7kd1zI — Ahmad Yousef (@EgyptianPlayers) November 29, 2019

"A colleague out for lunch messaged to say there had been an incident on London Bridge and he was unable to cross back over the river. I went straight to the window and saw hundreds of people running off the bridge down Tooley Street," Beer told CNN.

"People looked so panicked. It was haunting. There were at least half a dozen police cars and halted buses. Our building is now on lockdown, but we've not been given any concrete information," she added soon after the incident.