In what the police have said was a "terrorist incident", an attacker slashed a man in an east London metro station on Saturday. He was heard screaming "this is for Syria." The man has been taken into custody by the local police, Reuters reported.
One man suffered serious knife injures while two others had minor injuries, said the police. The incident occurred at Leytonstone Underground station of central London just after 1900 GMT, according to reports.
"We are treating this as a terrorist incident," said Richard Walton, who leads the counter-terrorism command at London's metropolitan police, in a statement to Reuters.
"I just saw a lot of people running, but I ignored it and kept walking to get my train, but suddenly what I saw I couldn't believe my eyes, and what I saw was a guy with a knife," an eyewitness told The Guardian.
The stabbing incident comes a month after the Paris attack on 13 November which killed 130 people. Islamic State had claimed responsibility for the attack.
Last week, British Prime Minister David Cameron won approval from parliament in favour of bombing the Islamic State. Warplanes bombed oil fields controlled by Isis on Thursday, Reuters reported.
It is very likely that the Islamic militants are planning a terror attack in the country; Britain has been on high alert since the Paris attacks.
Cameron said while militants view Britain as a "top target" despite foiled plots last year. According to the British security services, two-thirds of their time is spent countering international militants, much of which is connected to Syria, Reuters reported.
A similar incident occurred in May 2013 when a British army soldier Lee Rigby was brutally killed south of the Thames River by two Muslims, Reuters reported.