London:
British counter-terror police on Sunday questioned a 29-year-old man on suspicion of attempted murder after a stabbing attack in a London Underground train station that is being treated as a "terrorist incident".
Detectives from Britain's Counter Terrorism Command (CTC) searched a home in east London in connection with Saturday's attack at Leytonstone station, which left a 56-year-old man with serious knife injuries.
Amateur video footage of the incident showed one passer-by shouting "You're no Muslim" at the suspect as he was pinned down by officers in the ticket hall, where a pool of blood could be seen on the ground.
Sky News television reported that the man "apparently shouted 'this is for Syria'," although it did not quote anyone and the phrase is not evident from footage circulating online.
"As a result of information received at the time from people who were at the scene and subsequent investigations carried out by the CTC, I am treating this as a terrorist incident," said Richard Walton, the head of the police unit.
"I would continue to urge the public to remain calm, but alert and vigilant."
Saturday evening's attack came at the end of a week in which the British parliament voted to extend air strikes on the Islamic State jihadist group from Iraq into Syria.
The attack also came less than a month after the November 13 terror attacks in Paris, claimed by IS, that killed 130 people.
Police said the stabbing victim was in a stable condition in an east London hospital and his injuries were not believed to be life-threatening.
'You ain't no Muslim'
The attacker may have arrived at the station by train, said a passenger who arrived at Leytonstone shortly before the attack and had seen a man fitting the suspect's description.
"I don't know if it was the same gentleman that they caught, but he was very aggressive, he was a bit angry, shouting, abusing... he was on the train," a woman who gave her name only as Christina told AFP.
Amateur video shows a pool of blood and bloody footprints at the ticket gates of the suburban station.
Shouts are heard as the suspect is seen remonstrating with people before swinging at one of them.
Officers shout "Drop the knife!" and fire Taser electric stun guns.
"Who is this idiot?" one onlooker says of the suspect, adding: "Yes! Stupid idiot," after the man is Tasered.
Officers shout "Put the knife down!" and "Drop it now!" at the stunned man, who drops the short-bladed knife as he quivers on the ground.
One man then shouts at the suspect: "You ain't no Muslim, bruv! You're no Muslim, bruv! You ain't no Muslim!"
The hashtag #YouAintNoMuslimBruv was trending on Twitter on Sunday as people reacted to the news.
Salim Patel, 59, who runs the station shop, said: "I saw the guy attacking the victim, punching him so hard. The victim was screaming 'please, somebody help me. Help'.
"The attacker started kicking him on the floor. I think the victim was unconscious, he passed out. Then the attacker took a knife out and started stabbing him as he lay on the floor."
'Lone wolf' attack?
Terrorism expert Raffaello Pantucci said that although it was too early to say anything definitive about the incident, it was more than likely the suspect was a so-called "lone actor", or "lone wolf" attacker.
"At this point it looks like it might end up as that's what we're looking at," said Pantucci, of the Royal United Services Institute defence think tank in London.
"Because of the random targeting that we've seen happen, because we've seen no claim from any particular groups, because we haven't seen any evidence of him being part of being part of some bigger network."
Pantucci also said the speed with which police had labelled the attack a terrorist incident made it likely the attacker had tried to link his actions to Syria.
Britain's national terror threat level was raised in August 2014 to severe, the second highest of five levels, meaning an attack is considered highly likely.
London's transport system was hit in July 2005 by a series of suicide bomb attacks that killed 52 people.
A spokeswoman for Prime Minister David Cameron's Downing Street office said: "We are monitoring the situation closely as further details emerge."
Leytonstone station was open again Sunday, with a police officer standing guard outside.
Detectives from Britain's Counter Terrorism Command (CTC) searched a home in east London in connection with Saturday's attack at Leytonstone station, which left a 56-year-old man with serious knife injuries.
Amateur video footage of the incident showed one passer-by shouting "You're no Muslim" at the suspect as he was pinned down by officers in the ticket hall, where a pool of blood could be seen on the ground.
Sky News television reported that the man "apparently shouted 'this is for Syria'," although it did not quote anyone and the phrase is not evident from footage circulating online.
"As a result of information received at the time from people who were at the scene and subsequent investigations carried out by the CTC, I am treating this as a terrorist incident," said Richard Walton, the head of the police unit.
"I would continue to urge the public to remain calm, but alert and vigilant."
Saturday evening's attack came at the end of a week in which the British parliament voted to extend air strikes on the Islamic State jihadist group from Iraq into Syria.
The attack also came less than a month after the November 13 terror attacks in Paris, claimed by IS, that killed 130 people.
Police said the stabbing victim was in a stable condition in an east London hospital and his injuries were not believed to be life-threatening.
'You ain't no Muslim'
The attacker may have arrived at the station by train, said a passenger who arrived at Leytonstone shortly before the attack and had seen a man fitting the suspect's description.
"I don't know if it was the same gentleman that they caught, but he was very aggressive, he was a bit angry, shouting, abusing... he was on the train," a woman who gave her name only as Christina told AFP.
Amateur video shows a pool of blood and bloody footprints at the ticket gates of the suburban station.
Shouts are heard as the suspect is seen remonstrating with people before swinging at one of them.
Officers shout "Drop the knife!" and fire Taser electric stun guns.
"Who is this idiot?" one onlooker says of the suspect, adding: "Yes! Stupid idiot," after the man is Tasered.
Officers shout "Put the knife down!" and "Drop it now!" at the stunned man, who drops the short-bladed knife as he quivers on the ground.
One man then shouts at the suspect: "You ain't no Muslim, bruv! You're no Muslim, bruv! You ain't no Muslim!"
The hashtag #YouAintNoMuslimBruv was trending on Twitter on Sunday as people reacted to the news.
Salim Patel, 59, who runs the station shop, said: "I saw the guy attacking the victim, punching him so hard. The victim was screaming 'please, somebody help me. Help'.
"The attacker started kicking him on the floor. I think the victim was unconscious, he passed out. Then the attacker took a knife out and started stabbing him as he lay on the floor."
'Lone wolf' attack?
Terrorism expert Raffaello Pantucci said that although it was too early to say anything definitive about the incident, it was more than likely the suspect was a so-called "lone actor", or "lone wolf" attacker.
"At this point it looks like it might end up as that's what we're looking at," said Pantucci, of the Royal United Services Institute defence think tank in London.
"Because of the random targeting that we've seen happen, because we've seen no claim from any particular groups, because we haven't seen any evidence of him being part of being part of some bigger network."
Pantucci also said the speed with which police had labelled the attack a terrorist incident made it likely the attacker had tried to link his actions to Syria.
Britain's national terror threat level was raised in August 2014 to severe, the second highest of five levels, meaning an attack is considered highly likely.
London's transport system was hit in July 2005 by a series of suicide bomb attacks that killed 52 people.
A spokeswoman for Prime Minister David Cameron's Downing Street office said: "We are monitoring the situation closely as further details emerge."
Leytonstone station was open again Sunday, with a police officer standing guard outside.
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