Forces loyal to Libya’s beleaguered UN-backed government carried out airstrikes on Saturday to try to stop rebel troops advancing on Tripoli, raising fears the country may be heading back to full-blown civil war.

As the army of Khalifa Haftar, a military strongman in control of eastern Libya, claimed to have seized control of Tripoli's airport, EU officials warned that instability could trigger a fresh flow of migrants and refugees heading towards Europe.

A meeting of G7 foreign ministers called on Gen Haftar to halt his offensive and even his traditional supporters Russia and Egypt expressed concern that his sudden advance would plunge Libya into chaos.

The 75-year-old general’s advance on Tripoli appears to be a power play designed to strengthen his negotiating position ahead of a UN-brokered conference on Libya’s future scheduled for later this month.

Since the fall of Gaddafi in 2011, the country has been fractured and its government divided. A UN-backed government controls Tripoli with the support of several militias from western Libya while Gen Haftar is in charge of most of the east.