A man who went on a stabbing rampage in London's Russell Square on Wednesday, killing one woman and injuring five other people, has been arrested.

The assailant, a 19-year-old of Somali origin from Norway, was taken into custody after police received numerous reports of a man "attacking people with a knife" around 10:30 p.m. Police arrived on the scene minutes later and chased the suspect, tasering him, and tackling him when he refused to stop running. The man, who reportedly emigrated to the UK in 2002, was taken to the hospital for treatment and is now being detained in South London. 

Mark Rowley, the Met Police's assistant commissioner for specialist operations, said the attack was initially investigated for a terrorism link, according to the Independent. However, he said there is no evidence of radicalization and the attack was likely "triggered by mental health issues."

"Early indications suggest that mental health was a factor in this horrific attack," he said. "However we are keeping an open mind regarding the motive. As a precautionary measure, Londoners will notice an increased presence on the streets of officers, including armed officers today. We would urge the public to remain calm, alert and vigilant."

The victims were apparently selected at random. Two of the people injured in the attack remain in the hospital where they are being treated for non-life-threatening injuries and the other three have been released. The woman who died was a U.S. citizen, ambassador to the UK Matthew Barzun tweeted on Thursday. 

Heartbreaking news that a U.S. citizen was killed in #RussellSquare attack. My prayers are with all the victims and their loved ones.

— Matthew Barzun (@MatthewBarzun) August 4, 2016

There is reportedly still a large police presence in the area on Thursday and officials are asking people to come forward with any additional information.