Three men and a woman put a knife to a Brighton taxi driver's throat and robbed him of his cash and keys.

Three black men and a white woman flagged down Leo Carey as he was driving in Moulsecoomb, Brighton, early today.

They told him to stop at the nearby junction of Lewes Road and Coombe Road and one passenger produced a knife.

Mr Carey, in his thirties, was forced to hand over cash and his keys before the robbers fled.

Shaken but uninjured, he called Brighton and Hove Radio Cabs who alerted police and other drivers.

A search of the area was carried out but there was no trace of the offenders.

Police have appealed for witnesses to the 2.20am robbery to come forward.