A British Embassy convoy in Libya has been fired at during an attempted carjacking, as UK nationals were urged to leave the country immediately.

All staff escaped unscathed from the attack, which happened on the road between the capital Tripoli and Zawiya, which is en route to the Tunisian border.

Michael Aron, the UK's ambassador to Libya, wrote on Twitter: "There was an attempted carjacking on a British Embassy convoy this morning.

"Shots were fired at our vehicles but all staff safe."

The Foreign and Commonwealth Office (FCO) has updated its travel advice to state: "British nationals in Libya should leave now by commercial means."

The Libyan government said around 150 people have died in the country's two biggest cities during two weeks of fighting.

Rival armed militia groups have clashed in the capital Tripoli trying to control the main airport, leaving nearly 100 dead.

A large plane on the tarmac was destroyed in the violence.

In the eastern city of Benghazi, more than 50 have been killed, including many civilians, as security forces battled Islamist militants.

It has been the deadliest violence since the 2011 war that ousted Colonel Muammar Gaddafi, with the central government unable to impose order.

The United States shut its embassy on Saturday and safely evacuated its diplomats by road to neighbouring Tunisia, escorted by F16 fighter jets.

The British Embassy remains open but with reduced staff and a limited ability to provide consular assistance.

The FCO has warned about the "greater intensity of fighting" in Tripoli and the likelihood of further attacks on foreigners.

There are believed to be between 100 and 300 Britons in the north African country.

A number of foreign nationals have been shot dead in Libya since December and more attacks are expected.