One woman was killed and five others injured by a man with suspected mental health issues who went on the rampage with a knife in central London, an attack police said could be linked to terrorism.
Armed police were called at 10:33 p.m (2133 GMT) after a man with a knife started to attack people in London’s Russell Square, an elegant park near the site of a 2005 suicide bombing.
“Early indications suggest that mental health is a significant factor in this case and that is one major line of inquiry,” London Metropolitan Police Assistant Commissioner Mark Rowley told reporters.
“But of course at this stage we should keep an open mind regarding motive and consequently terrorism as a motivation remains but one line of inquiry for us to explore,” said Rowley, who is Britain’s most senior anti-terrorism officer.
Police, who arrived within five minutes of being called, used a Taser electric shock gun while arresting the 19-year-old suspect. The investigation is being handled by the homicide command with support from the counter-terrorism officers.
The woman was treated at the scene but was pronounced dead a short time later. The other injured people – one woman and four men – are being treated, Rowley said.
Britain says its terrorist attack threat level remains at “severe”, the second-highest level, meaning a strike is “highly likely”. London police had already promised to deploy more armed officers after a spate of deadly attacks in France, Germany and Belgium.
London counter-terrorism police chiefs have previously warned that Islamic State was seeking to radicalize vulnerable people with mental health issues to carry out attacks. In some operations, police commanders have taken advice from specialist psychologists.
London was hit by coordinated suicide bombings on July 7, 2005, when four Islamist extremists targeted three underground trains and one bus, killing 52 people.
One of the bombs was detonated on an underground train traveling between Kings Cross and Russell Square while another bomb was detonated on a bus in Tavistock Square, a short distance from Russell Square.
Since then, dozens of plots have been foiled and there have been smaller-scale attacks, such as the killing of an off-duty soldier on a street in south London by two extremists in May 2013.
A man who attacked passengers at a London underground train station in December was jailed for life earlier this month. The judge said the attacker was suffering from paranoid schizophrenia at the time of the offence but that he may have been motivated by events in Syria.
“Londoners will wake up and in the morning they will notice an increased police presence on the streets, including armed officers,” Assistant Commissioner Rowley said.
“This is there to provide reassurance and safety. We ask the public to remain calm, vigilant and alert,” he said.