In a statement posted on its website today, the interim government says the fighting between rival militias caused the huge blaze, which could trigger a "humanitarian and environmental disaster."
Libyan TV stations are calling on residents to evacuate areas near the airport. Social networking sites posted images of billowing black smoke over Tripoli skyline.
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, under control of rival militias from the western mountain town of Zintan.