One person was killed and five others were injured in a knife attack in central London late Wednesday night.
Scotland Yard counterterrorism command was investigating the stabbings in the city's Russell Square — police were called there around 10:30 p.m. local time on reports of a man attacking people with a knife, the Metropolitan Police said.
"Early indications suggest that mental health was a factor in this horrific attack. However we are keeping an open mind regarding the motive and terrorism remains one line of inquiry being explored," Assistant Commissioner Mark Rowley, from the Metropolitan Police, said.
One woman died at the scene from her injuries, she was believed to be in hers 60s. Two other women and three men received "various injuries" during the attack, according to the Sccotland Yard. No further indictations were given about the severity of the injuries.
Police used a Taser to detain and arrest a 19-year-old man. The suspect is currently in custody at a London hospital.
Rowley added that "As a precautionary measure, Londoners will wake up this morning to 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 Metropolitan Police Service’s Homicide and Major Crime Command is investigating the crime and is supported by officers from the Counter Terrorism Command.
The Mayor of London, Sadiq Khan, said that that police are working "extremely hard" to investigate exactly what happened "and to keep the rest of us safe."
He also urged Londoners to remain "calm and vigilant" and to report anything suspicious to police, and added: “The safety of all Londoners is my number one priority and my heart goes out to the victims of the incident in Russell Square and their loved ones."
Russell Square, where the attack occurred, is less than one mile from the University of London and about two miles from Buckingham Palace and right by the British Museum, an area frequented by visitors and tourists.
The attack comes a day after the Met Police had announced it would add patrols to the streets of London amid concerns that a terror attack might be imminent.
Met Police chief Sir Bernard Hogan-Howe told Sky News it would be "foolish to ignore" the slew of attacks that have hit Europe over the last few weeks: "It is important that we get officers out there with firearms to respond where necessary."
A few days ago, Hogan-Howe had also warned that an attack in the UK similar to those that have hit Europe is a case of "when, not if."