Manchester Arena explosion
A police van and an ambulance are seen outside the Manchester Arena.Reuters

Twenty-two people were killed while several were injured in an explosion which took place at a concert of American singer Ariana Grande in Manchester in the United Kingdom on Monday, May 22.

Though the UK has not experienced terror attacks as continental Europe of late, yet there have been instances of terrorist activities on its soil over last few years.

Here are some terrorist attacks in the UK that took place in the past:

UK Parliament on March 22, 2017: A 52-year-old Briton called Khaled Masood mowed down pedestrians on the Westminster Bridge, killing four persons, including two women and injuring many others. Masood crashed his car into the railings outside the Parliament house and then ran into the New Palace Yard where he stabbed a police personnel. He was shot dead by the police.

Leytonstone tube station on December 6, 2015: A 30-year-old taxi driver called Muhiddin Mire stabbed three people in Leytonstone Underground station in East London. He was found to be affected with paranoid schizophrenia who randomly attacked people. One of his victims was seriously injured. Mire was found guilty of attempting to murder in June 2016.

Woolich in May 22, 2013: It was exactly four years ago that a British soldier Lee Rigby was killed in a terror attack in Woolich in southeast London. Two assailants hit Rigby, 25, with a car before stabbing and trying to behead him in the public outside the army camps. The violent incident was also video-recorded.

Northern Ireland on March 7, 2009: Two British soldiers of 38 Engineer Regiment were shot dead in Antrim town in Northern Ireland., outside the Massereene Barracks. Four other persons, including two soldiers and two civilian delivery men, were also injured. The Real IRA group later claimed responsibility for the attack.

London underground bombings on July 7, 2005: It is the most horrific of terror attacks in the UK (also termed as 7/7 or the UK's own 9/11) in which 52 people were killed and over 780 were injured. The terrorists carried out a series of suicide bomb attacks in three underground trains during the rush hour. A fourth killer had blew himself up on board a double-decker bus in Travistock Square in London's Bloomsbury. This incident happened a day after London won the bid to host the 2012 Olympics.