The NATO airstrike that reportedly killed several members of Colonel Gaddafi’s family has prompted an angry backlash against the UN and at least two western embassies.

The UN says its staff are leaving Tripoli after a mob attacked its offices, adding that the Libyan government has apologised.

Britain is expelling the Libyan ambassador to London after its embassy in Tripoli was attacked and burned. Italy has condemned what it calls a “grave and vile” act after its embassy was damaged.

Russia says it has serious doubts over NATO’s denials that it is targeting Gaddafi or his family, but is aiming to destroy command and control centres.

The Bishop of Tripoli has reportedly confirmed the Libyan government’s claims that the leader’s youngest son was killed.

Saif al-Arab is described as having had a limited role in the power structure.

Earlier news of his death was greeted with scepticism in the rebel stronghold of Benghazi where some thought it was a ploy by Tripoli to gain sympathy.