Eastern Libyan forces on Friday seized the former Tripoli International Airport on the southern outskirts of the capital, a spokesman said.
Tripoli is home to Libya’s internationally recognized government.
Ahmed Mismari also told reporters his forces were in control of Tarhouna and Aziziya, two towns near Tripoli. He said five of his troops had been killed.
Armed clashes broke out on Friday south of Libya’s capital Tripoli between the pro-government alliance and forces loyal to eastern strongman Khalifa Haftar.
The escalation surprised the United Nations. UN secretary-general Antonio Guterres had been in the capital this week to help organize a national reconciliation conference planned for later this month.
But on Thursday LNA forces took Gharyan, about 80 km south of Tripoli after skirmishes with forces allied to Tripoli-based, UN-backed Prime Minister Fayez al-Serraj.
They further moved north coming as close as 40 km to Tripoli by taking the village of Suq al-Khamis after some fighting, a resident and an eastern military source said.
In the evening, the LNA said they had taken control of the areas of Qasr ben Ghashir and Wadi al-Rabie on the southern ouskirts of Tripoli, near the former Tripoli International Airport, closed since a city battle in 2014.
There was no independent confirmation, but a video posted online purportedly showed LNA fighters inside Qasr ben Ghashir.