A massive blaze continued to rage at a fuel depot near Tripoli's crippled airport on Tuesday while a Libyan paramilitary fighter jet crashed in the eastern city of Benghazi during fighting with Islamist groups.
Authorities said the Italian government and national energy giant ENI were to send seven fire-fighting planes to help combat an inferno raging at an oil depot on the outskirts of the capital.
Italy will also send teams to help firefighters tackle the blaze, which was sparked during fighting Sunday night between Libyan militias and has been raging ever since, a government statement said.
In Benghazi, General Sagr al-Jerouchi, chief of air operations for dissident ex-general Khalifa Haftar, said it was not immediately clear if the plane had been hit by gunfire or suffered a malfunction before crashing and exploding.
He added that the pilot had safely ejected, which was confirmed by a witness who said he saw a parachute open before the plane crashed.
The witness said the warplane had just attacked Islamist positions.
Two weeks of fighting between militias for control of Tripoli airport and between Islamists and a former general in Benghazi has killed scores of people and prompted several countries to urge their citizens to leave Libya.
The Tripoli fire erupted when a rocket struck a tank containing more than six million litres (1.6 million gallons) of fuel before spreading to a second storage site in what the government called a "very dangerous" development.
The authorities feared the blaze could spread still further to a natural gas reservoir, where 90 million litres are stored, amid fears that a huge fireball could cause carnage over a wide area.
While the oil burns, motorists in Tripoli are suffering severe petrol shortages, as service stations have closed over fears for the safety of staff in light of the fighting.
On Monday, the government appealed to several countries for help and Italy, as well as Greece, said aid would be contingent on a halt in the fighting.
In its statement Tuesday, the government again called for a ceasefire.
Combat raged overnight, with a number of explosions heard, but the situation was relatively calm on Tuesday morning.
On Monday, top world leaders urged an immediate ceasefire and called on the UN "to play an essential role in facilitating the political process" to restore stability to Libya.
The clashes, the most violent since the 2011 revolt, started with a July 13 assault on the airport by armed groups, mainly Islamists.
The attackers are battling to flush out fellow former rebels from the hill town of Zintan, southwest of Tripoli, who have controlled the airport for the past three years.
Weekend fighting in Benghazi, cradle of the 2011 revolution that ousted dictator Moamer Kadhafi, killed dozens of people, mostly soldiers.
Combat erupted Saturday when Islamists attacked the headquarters of a special forces unit near the city centre. One of the few regular army units located in Benghazi, it backs an anti-Islamist campaign launched by Haftar in May but has not placed itself under his command.
Since May, clashes have taken place in Benghazi on an almost daily basis.
As the lawlessness spreads, France was evacuating its nationals from Libya, a government source said.
There are fewer than 100 French nationals in Libya and they will be taken out of the country by ship, the source said, adding that the operation would be over by the afternoon.
Several countries, including Britain, Germany and Egypt, at the weekend advised their nationals to leave immediately.
The United States for its part evacuated its embassy, citing a real risk because of fighting between troops loyal to the Libyan government and Islamists.
The exodus of foreign workers will further hit the strife-torn country, with the health ministry warning of a shortage of medical staff after the Philippines announced it was withdrawing its citizens, including 3,000 doctors and other healthcare workers.