(CNN)Several deadly terror attacks have struck the UK in recent decades -- mostly in London.
Monday's blast outside a Manchester arena killed at least 22 people, with police saying, "We are currently treating this as a terrorist incident."
If the incident is proven to be a terror attack, it will be the latest in a long list of violence stretching back to the 1990s.
In the '90s, a wave of bombings came from the Irish Republican Army, which fought against British rule in Northern Ireland. In more recent times, the deadliest attack came on July 7, 2005.
Here's a timeline of deadly terror attacks and bombings in the mainland UK stretching back nearly three decades:
Westminster Bridge and Parliament
March 22, 2017
A lone assailant plowed a SUV into crowds of people gathered on London's Westminster Bridge, then crashed the vehicle onto the sidewalk. The attacker then stabbed an unarmed police officer who was standing guard at Carriage Gates, an entrance into a cobbled courtyard frequently used by Members of Parliament and staff. Police shoot and kill the attacker..
Deaths: Five people died including a Romanian visitor who succumbed to her injuries a few weeks later.
Attacker: Khalid Masood, a 52-year-old British man, who was known to authorities for links to "violent extremism." Massod had a checkered past involving a series of aliases and a string of convictions for violence and possession of weapons.
May 22, 2013
Two attackers drove a car into a British solider, then hacked him with knives and a cleaver. The soldier was wearing a Help for Heroes T-shirt when he was attacked in Woolwich, in an incident near a military barracks in southeast London. Cellphone footage showed one of the attackers clutching a meat cleaver in his bloody hands, ranting that the killing was "an eye for an eye, a tooth for a tooth" for British soldiers killing Muslims overseas.
Death: British soldier Lee Rigby, 25, infantryman, drummer and machine gunner who served in Afghanistan and Cyprus, was killed.
Attacker: Two men, Michael Adebolajo and Michael Adebowale, were found guilty of the murder of Rigby. Adebolajo declared himself a warrior for Allah in the courtroom.
London Underground attacks
July 7, 2005
Three suicide bombings occurred within 50 seconds of each other on three different trains traveling through London Underground stations. The locations targeted are a train outside Liverpool Street station, another one outside the Edgware Road station and a train traveling between King's Cross and Russell Square stations. A fourth suicide bomb explodes on a double-decker bus at Tavistock Place. Public transit comes to a halt in London.
Deaths: The attacks kill 52 people and injure hundreds more.
Attackers: Four suicide bombers are identified as Shahzad Tanweer, Hasib Hussain, Mohammed Sadique Khan and Germaine Morris Lindsay.
Admiral Duncan pub
April 30, 1999
A series of nail bombings occurred in a spate of 13 days. The first occurred in a supermarket, then at a street in the center of the Bangladeshi community and finally the Admiral Duncan pub in London's gay district.
Deaths: Three people died in the attack on the Admiral Duncan pub.
Attacker: A 23-year-old self-declared "Nazi" -- David Copeland -- was sentenced to six life terms.
February 9, 1996
A 3,000-pound bomb detonated in London's Docklands area. The blast, which led to conviction of an IRA member, injured more than 30 people and caused damage estimated at around $170 million. The bombing ended the Irish Republican Army's 17-month ceasefire.
Deaths: Two people died.
Attacker: IRA member James McArdle, convicted in the bombing, was freed in 1998 as part the peace process in Northern Ireland.
April 24, 1993
An IRA truck bomb devastated part of London's financial district. The blast shattered hundreds of window and brought down a medieval church.
Deaths: One person died and 44 were wounded.
March 20, 1993
Two bombs left in the trash bins of a shopping area in Warrington, northern England, exploded. The bombing sparked outrage because it targeted ordinary people and killed two children.
Deaths: Two boys aged 3 and 12 died, and dozens were injured by the two bombs.
Attacker: The IRA admitted planting the bombs, but the bombers have not been identified.
April 10, 1992
An IRA car bomb ripped through London's financial district, shattering hundreds of windows causing injuries from flying glass. The bomb so badly damaged the Baltic Exchange's office that it had to be demolished.
Deaths: Three people were killed and 91 wounded.