Zakaria Bulhan has been identified as the man who was arrested on suspicion of murdering one American woman and injuring five other people in a knife attack in Russell Square in central London late Wednesday, CBS News reported citing American law enforcement.

The attack took place on the eastern corner of Russell Square and triggered fears of terrorism following months of high security across Europe after attacks in Paris, Brussels and Germany. Authorities, however, pointed to mental health issues and said they had no reason to suspect that radicalization had played any part in the attack.

“Whilst the investigation is not yet complete, all of the work that we have done so far increasingly points to this tragic incident as having been triggered by mental health issues,” said Assistant Commissioner Mark Rowley of the Metropolitan Police, the New York Times reported. “At this time we believe this was a spontaneous attack and the victims were selected at random.”

London Knife Attack A police officer stands guard at the scene of a knife attack in Russell Square in London, Britain August 4, 2016. Photo: Reuters/Neil Hall

British police said Bulhan is a 19-year-old Norwegian citizen of Somali background who moved to Britain in 2002. Norwegian authorities were cooperating in the ongoing investigation along with British authorities. CBS reported that Bulhan was a patient at a psychiatric facility close to the scene of the attack.

The knife attack left Darlene Horton of Florida dead and wounded five other people who were identified as citizens of Australia, Britain, Israel and the U.S. Three of the victims have been treated for their wounds and released from the hospital. Officers used a stun gun to subdue and capture Bulhan. Police have said they believe the victims were selected at random.

The attack took place in the popular Bloomsbury neighborhood that is home to the British Museum as well as hotels and restaurants. London Mayor Sadiq Khan praised the swift police reaction saying they were doing an “increasingly difficult job,” the BBC reported.

Wednesday evening’s knife attack took place after British authorities announced the start of Operation Hercules. The operation is meant to up security with an additional 600 officers patrolling in London to protect against any potential terror attack.