Police arrested on Sunday two men over the killing of a teenager in London.

The victim, believed to be 18, was stabbed in an area north of Kings Cross rail station on Sunday morning after an argument with a group of men. He was taken to Whittington hospital where he later died.

"The full circumstances are still being investigated," Scotland Yard said in a statement. "We are keeping an open mind regarding the motive and are searching for the murder weapon or weapons."

"Two male youths both in their teens were arrested nearby."

Police have launched a campaign to discourage knife crime in the capital, while newly-elected London Mayor Boris Johnson has made tackling youth violence one of his priorities.