Libya is plagued by political assassinations and remains awash with illegal arms, including the components of chemical weapons, according to the United Nations.

A report to the Security Council yesterday from the UN mission in Libya paints a bleak picture more than two years after British and French air power helped rebels overthrow Colonel Muammar Gaddafi.

"Targeted political assassinations, criminal activity and attacks and threats against the diplomatic community continue," it said.

The failure to demobilise militias is seen as a central cause of the turmoil with thousands of gunmen still at large. "Revolutionary brigades" have blockaded the oil export terminals, reducing production from 1.6 million barrels a day to 200,000.