Jewish security chiefs are in close contact with the police after an Israeli woman was reportedly among victims of a fatal stabbing in Russell Square last night.

A 19-year-old man was arrested on suspicion of murder after a knife attack in central London in which a woman was killed and five other people injured.

Counter-terrorism officers are supporting the investigation into the incident, while Scotland Yard said early indications suggest mental health “was a factor”.

Armed officers raced to the scene in Russell Square on Wednesday night following reports that a man armed with a knife was targeting people.

A woman, believed to have been in her 60s, was pronounced dead at the scene, while two other women and three men were hurt.

According to unconfirmed reports the victim was American and the injured were British, Israeli and Australian.

The Community Security Trust, who released their 6-month anti-Semitism figures earlier today, said they were in contact with the police.

They tweeted: “CST in close contact with met police since early today regarding possible terror stabbing in Russell Square.”

Board of Deputies of British Jews Vice President Marie Van der Zyl commented “Our sympathy goes to the victims of the stabbing attack in Russell Square. We must all remain vigilant.”

A police taser was discharged during the arrest of the suspect. He received hospital treatment and was then taken into custody at a police station in south London.

The Metropolitan Police’s Homicide and Major Crime Command is leading the investigation, supported by counter-terrorism officers.

Assistant Commissioner Mark Rowley said: “This was a tragic incident resulting in the death of one woman and five others being injured. Early indications suggest that mental health was a factor in this horrific attack; however,we are keeping an open mind regarding the motive.

“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.”

In an earlier statement, police said terrorism was “one line of inquiry being explored”.

London Mayor Sadiq Khan called for the public to remain “calm and vigilant”.

He said: “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.”