TORONTO -- London suffered yet another terrorist attack on Friday afternoon when a man wearing a fake explosive vest stabbed several people, killing two, near the famous London Bridge before he was shot dead by police.

The incident occurred just weeks after the U.K.’s national terrorism threat level was downgraded from “severe” to “substantial” for the first time in five years. According to the Joint Terrorism Analysis Centre, a severe rating indicates that an attack is “highly likely” while substantial means it is “likely.”

In May and September 2017, the country’s terror threat was even briefly raised to “critical.”

As the world reacts to this latest attack, CTVNews.ca has compiled a list of some of the major terrorist incidents that have rocked London in recent memory.

Sept. 15, 2017

A homemade bomb planted in a rush-hour subway car exploded in London, injuring 29 people and prompting authorities to raise Britain's terrorism threat level to "critical," meaning another attack may be imminent.

The early morning blast sparked a huge manhunt for the perpetrators of what police said was the fourth terrorist attack in the British capital that year. The Islamic State group claimed responsibility for the attack, which it said was carried out by an affiliated unit.

June 19, 2017

A man drove a rented van into worshippers leaving evening prayers at a mosque in London’s Finsbury Park neighbourhood. He killed a 48-year-old man and injured 12 others in the incident. Bystanders caught and restrained the attacker, Darren Osborne, until police arrived. He was sentenced to at least 43 years in prison. 

June 3, 2017

Three assailants inspired by the Islamic State drove a van into pedestrians on London Bridge before exiting the vehicle and stabbing more people at the nearby Borough Market. Eight people died, including the three attackers who were shot dead by police, and dozens were injured in the attack. Canadian Christine Archibald, a 30-year-old woman from British Columbia, was one of those killed in the attack.

March 22, 2017

Khalid Masood drove a rented SUV across a crowded Westminster Bridge, leaving three dead and dozens wounded. Then he jumped out and attacked Const. Keith Palmer, an officer guarding Parliament, stabbing him to death before being shot to death by police.

May 22, 2013

Two British-born, al Qaeda-inspired extremists stabbed off-duty soldier Lee Rigby to death on a busy south London street. The men ran Rigby down with their vehicle and then used a cleaver to hack him to death.

Images of attacker Michael Adebolajo holding a butcher knife and cleaver with bloodied hands in the moments after the killing shocked people around the world and sparked fears of Islamist extremism in Britain. Adebolajo and his accomplice were sentenced to life in prison.

July 7, 2005

In the worst peacetime attack on Britain this century, four al Qaeda-inspired bombers blew themselves up on three subway trains and a bus in London, killing 52. Three of the bombers were British-born, all of Pakistani descent; the other emigrated from Jamaica.

-With files from The Associated Press