CAIRO — A fire at the oil depot for the airport in Libya’s capital raged out of control Monday after being struck in the crossfire of warring militias battling for control of the airfield, the latest violence to plague the country as foreigners flee the chaos.
Libya’s interim government said in a statement that the fire could trigger a ‘‘humanitarian and environmental disaster’’ in Tripoli, appealing for ‘‘international help’’ to extinguish the inferno. It did not say what it specifically needed.
The blaze had spread to a second depot by Monday afternoon, the government said. It was unclear if there were any injuries from the fire.
‘‘The government appeals to all concerned parties to immediately stop firing as the situation has become very grave,’’ the government said.
Libyan television stations called on residents to evacuate areas within a 3-mile radius of the airport. Many Libyan families scrambled to leave. Black smoke billowed over the Tripoli skyline.
Mohammed al-Harari, the spokesman for the Libyan National Oil Company, said the oil depot had a capacity of 1.6 million gallons and that if the fire was not brought under control, it could ignite liquid gas nearby.
Fire trucks from several nearby cities and towns have been deployed to help extinguish the blaze, said a Libyan security official, speaking on condition of anonymity because he is not authorized to talk to journalists.
The battle for control of the airport began two weeks ago when Islamist-led militias — mostly from the western city of Misrata — launched a surprise assault on the airport, which has been under control of a rival militia from the western mountain town of Zintan. It wasn’t clear whose fire started the oil depot blaze.
The Health Ministry said Sunday that the fighting has so far killed 79 people and wounded more than 400.
More than three years after dictator Moammar Khadafy’s downfall, Libya is witnessing one of the worst bouts of violence amid growing lawlessness in the country.
Libya’s interim government, which relies on militias filled with rebels who battled Khadafy’s forces for security, now finds itself unable to rein them in.
The fighting has sparked many to flee the country. On Saturday, the United States evacuated its diplomats from Tripoli to neighboring Tunisia and shut its embassy.
The United Nations Support Mission in Libya and the International Committee of the Red Cross have already withdrawn their staff as well. European nations are warning their citizens to immediately leave the country.
German embassy staff in Tripoli were evacuated on Monday, Foreign Ministry spokeswoman Sawsan Chebli said in Berlin.
They will be sent back ‘‘as soon as the security situation allows,’’ she said.
Austria also removed its diplomatic staff Monday and urged citizens to leave the country as quickly as possible.
Meanwhile, Egyptian ambassador to Libya Mohammed Abu Bakr, who runs the embassy’s affairs from the Foreign Ministry in Cairo, denied on Monday that there were some Egyptian nationals among the 23 people killed when a rocket slammed into a house in Tripoli on Saturday.
Abu Bakr said he was officially informed about this by the Libyan Interior Ministry and did not elaborate.
The Egyptian Foreign Ministry said on Sunday that there were some Egyptian nationals among the 23 killed.
The fighting in Tripoli is partly inspired by the campaign of Libyan troops loyal to former General Khalifa Hifter, who vowed in May to rid the country of Islamist militias. Hifter and his self-proclaimed national army have focused their fight in Benghazi, where daily battles with the militias have become stalemated.
Hifter has won support from Libyans who fear the influence of extremists, especially in eastern Libya. But his campaign has also stirred new divisions and violence, across the country.
In the absence of a strong central government, the militias who helped oust Khadafy never put down their arms. They became security units, paid by the government and aligned with political factions or local tribal interests.
In September 2012, militants attacked the US diplomatic mission in Benghazi, killing the ambassador, Chris Stevens, and three other Americans.