Armed police are attending an apparent hostage situation taking place inside Bella Italia restaurant in London's Leicester Square.

A security source has told ITV News that one man is in possession of a knife and is holding a woman hostage.

The source said that four people in total are inside the premises and all know each other.

Diners in nearby restaurants have been told to stay inside.

A Metropolitan Police statement confirmed that police are attending the scene in Irving Street and said that the incident is not terror-related.