There are fears that the Libyan conflict could escalate even further as foreign powers continue to avail weapons to the factions engaged in the power dispute.

Turkish drones have helped drive eastern Libyan forces back from Tripoli this month, but at the same time Russia is said to be reinforcing them with warplanes, raising the stakes in a stalemated civil war that has partitioned the country.

Backed by the United Arab Emirates, Russia and Egypt with arms, mercenaries and air strikes, according to U.N. experts, Eastern commander Khalifa Haftar and his Libyan National Army (LNA) had last summer advanced into Tripoli's southern suburbs before their offensive stalled.

However, aid from Turkey helped turn the tide with air defences and drone strikes that neutralised LNA air power before hammering its ground troops and long supply lines this month.

"In the last few weeks, there has been a significant change in balance in Libya," said a senior Turkish official, crediting Turkish drones and "untrained soldiers" operating LNA air defences.

It led, over the past month, to the LNA's sudden loss of a string of towns near the Tunisian border, a crucial air base, a dozen of its own air defence systems and most of its foothold in Tripoli. With them went Haftar's hopes of victory.

Over the same period, Russian military personnel have delivered some 14 MiG 29 and Su-24 fighter jets to the LNA's Jufra air base in central Libya, the U.S. military said this week. They are aircraft that could again turn the tide of war.

A Russian member of parliament and the LNA have denied the aircraft arrived.

Libya is once more on the brink after years of chaos that followed the uprising against Muammar Gaddafi in 2011, leading to rival administrations in Tripoli, in the west, and Benghazi in the east.

Russian and Turkish officials spoke last week and issued a statement agreeing on the need for a ceasefire, a possible sign they have hashed out a backroom deal to avert a direct confrontation after the arrival of the Russian jets.