One woman was said to have been fatally wounded, while another five people were injured in a knife attack in London's Russell Square which is close to the British Museum and the University of London.

Police were called to Russell Square at 10.33 p.m. local time (21.33 UTC) on August 3 after reports of a man seen in possession of a knife injuring people.

Police used a taser gun to arrest the suspect, who officials said was aged 19.

The female victim was treated at the scene but was pronounced dead a short time later.

"Terrorism is one possibility being explored at this stage," police said in a statement, while later also indicating that mental health issues might also have played a role.

The condition of the victims is not yet known. One of them is believed to be an American citizen.

Extra police have been deployed in the area. The attack came on the same day that police announced that more armed officers were to be deployed on public patrol as part of anti-terrorism plans.

On July 7, 2005, as part of a coordinated Islamist attack, a bomb was detonated on a train travelling between the King's Cross St. Pancras and Russell Square underground stations, resulting in the deaths of 26 people.

More armed police

London is deploying 600 extra, armed police to join the existing 2,200 firearms officers in the face of 'all manner of threats.' But most of the UK capital's 31,000 police officers are not armed.

Launching the initiative with London's new mayor, Sadiq Khan, Metropolitan Police chief Bernard Hogan-Howe said "you need firearms officers who will use force to stop those attackers."

After terrorist attacks in France and in southern Germany in the last month, the UK is also on high alert. The country has not had a major terror attack since 2005, but reports suggest it remains a target.

"Anyone who's been following events in Europe over the past few weeks will understand why we want to show our determination to protect the public," Hogan-Howe said.

"In some of our big iconic locations, we've already got armed patrols - if you look at Parliament, Downing Street - so it's not entirely new," he said. "I think people understand that where you are going to have people as enemies who've got guns, we've got to have guns."

Khan told reporters that while Britain's "severe" threat level remained unchanged, "in light of recent deadly attacks in Europe it is important we are prepared should the unthinkable happen," he said ahead of the initial police deployment on Thursday.

"We will see more armed officers on our streets, but there is no reason to be alarmed," Khan said. "All of our police officers are playing their part and working closely with all of our communities to prevent the possibility of an attack."

(DW)