Jodie Parry, who was in her hotel room when she heard a "commotion" in the street, told the BBC that the attacker ignored police as they screamed at him to stop running.

Police raced to Russell Square, a popular tourist area near the British Museum in Bloomsbury, shortly after 10.30pm on Wednesday after reports of a man armed with a knife assaulting 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.

"I looked out the window and I saw a black man who was running down the street, and as he was running down the street he was turning to see if the police were coming close," Ms Parry said.

"I could hear the policeman screaming 'stop, don't move, don't go any further, just stay where you are' and he turned around and continued running. He just wasn't prepared to stop."

She added: "He was actually carrying a knife in his hand and he had blood on his hands."

Ms Parry said the attacker was out of her sight when he was restrained by police.

"They had actually gone out of my vision at that point, but I did hear the Taser, and at that point I just heard a little scream and then it kind of went silent," she said.

Read report of the attack here.