>> On the rampage with a knife in Central London, a 19-year-old arrested on suspicion of murder after an American woman was killed on Wednesday night. Five other people injured in the attack, Reuters UK correspondent Costas Pitas is in London.>> We now know from police that the attacker is a Norwegian man of Somali origin, and that he's 19 years old.
The victims, one woman has lost her life, she's an American citizen and there were four people who were injured. One an American, an Australian, an Israeli, and a British citizen.>> Britain's counter terrorism unit have been called in to help investigate, but police say no evidence of radicalization has been found to link the incident to terrorism.
>> The police said quite early on in their investigations overnight into the early hours of the morning that mental health issues were a particular concern. Regarding this incident and in the last few hours they've steered increasingly away from terrorism as a motivation. Britain's threat level is on severe which means an attack is highly likely.
There's no indication that that level will change as a result of today's incidents at least for the moment. What does this mean for London as well? More police officers, more armed police officers are going to be on the streets as the result of the decision that was made yesterday.
Obviously Europe and Western Europe in particular is on high alert, there have been terrorist incidents in Brussels, in France, in Germany, but also in Turkey.>> Armed police were called to the scene in Russell Square at 10:30 PM. They arrived within six minutes using a taser gun to subdue the suspect before arresting him.
No shots were fired. Just hours before the attack, London's police chief announced the deployment of an additional 600 armed officers across the capital. London mayor, Sadiq Khan, has urged the public to remain vigilant and alert.