Bullet holes are seen in a car at a checkpoint on the Egyptian border with Sudan and Libya, which was attacked on Saturday, in Wadi al-Gadid governorate July 19, 2014. Gunmen killed 21 Egyptian military border guards near the frontier with Libya on Saturd
Bullet holes are seen in a car at a checkpoint on the Egyptian border with Sudan and Libya, which was attacked on Saturday, in Wadi al-Gadid governorate July 19, 2014. Gunmen killed 21 Egyptian military border guards near the frontier with Libya on Saturday, highlighting a growing threat from an area that security officials say has become a haven for militants seeking to topple the Cairo government. REUTERS/Al Youm Al Saabi Newspaper (EGYPT - Tags: CIVIL UNREST POLITICS) NO COMMERCIAL OR EDITORIAL SALES IN EGYPT REUTERS/Al Youm Al Saabi Newsp

The United Kingdom's Foreign and Commonwealth Office has advised all Britons currently in Libya to leave the country, citing the ongoing and greater intensity of fighting in Tripoli and wider instability. It likewise has issued a travel ban against the north African nation.

The ban was prompted after a British diplomatic convoy was almost car-jacked on Sunday on the road between Tripoli and Zawiya. Shots were fired but no one was injured.

"British nationals in Libya should leave now by commercial means," the ministry said on its Web site. It noted that a number of foreign nationals have been shot dead in Libya since December 2013. Further attacks against foreigners are likely and could be opportunistic.

BBC News reported there are at least 100 and 300 Britons believed to be currently in Libya.

The ministry noted the high threat of terrorism including kidnapping. Since January 2014, a number of foreign nationals have been kidnapped, including in Tripoli.

It warned U.K. nationals to avoid demonstrations or large gatherings of people. "If you become aware of any nearby violence you should leave the area immediately."

"Violent clashes between armed groups are possible across the country, including in Tripoli, particularly at night. Fighting can break out in many places and at short notice. It can become serious quickly putting those in the area at risk. Remain vigilant at all times."

The ministry said the British Embassy in Libya remains open but operates on reduced staff. "The Embassy's ability to provide consular assistance in Libya is very limited."

The Foreign Office advised Britons to coordinate with their airline or travel company for further information before travelling because airports may change their flight schedule without notice.

"If you are a British national in Libya and you have concerns about how to leave the country, please call +218 (0)21 335 1084/5/6."