Four people, including a London police officer who was stabbed and the alleged assailant, were killed in terror attack that saw more than 40 people injured outside the Parliament building on Wednesday in an act described as "sick and depraved" by British Prime Minister Theresa May.
The officer who died, is identified as 48-year-old Keith Palmer, he was not armed. Palmer was a husband and father, serving for 15 years with the Metropolitan Police.
Acting Deputy Commisssioner and Head of Counter Terrorism Mark Rowley told reporters they believe there was only one attacker. Among the injured were three police officers.
The knife-weilding attacker stabbed a police officer and was shot on the grounds outside Britain's Parliament, sending the compound into lockdown.
The threat level for international terrorism in the U.K. was already listed at severe, and will remain so, according to May. The attack came on the one-year anniversary of the terror attacks in Brussels in which 32 people were killed and more than 300 injured.