Police have cordoned off part of London's Leicester Square after a man took a woman hostage with a knife in a restaurant.
The man is believed to be holding the woman against her will in a branch of Bella Italia, and two other people are inside, police said.
Officers have surrounded the building and are negotiating with the man.
A Met spokesman said: "A male who is intimating he has got a knife is holding a woman against her will. Two other people are inside the venue and we are on the scene seeking to engage with him.
"It is not terror-related".