Libya's UN-backed government said at least 21 people have been killed and 27 wounded in fighting near Tripoli.
The Libyan National Army (LNA) forces, led by Gen. Khalifa Haftar, have been carrying out a multi-pronged attack from the south and west of the city since April 4.
On April 7, the LNA said it had carried out its first air strike, a day after UN-backed Government of National Accord (GNA), led by Fayez Sarraj, hit them with air strikes on Saturday.
Fighting has continued around the disused international airport south of the capital that Gen. Haftar earlier said his forces had seized.
Forces loyal to the GNA have slowed the advance and yesterday, a GNA spokesman told Al-Jazeera TV that the GNA now intended to "cleanse" the whole of the country.
U.S. Africa Command, responsible for U.S. military operations and liaison in Africa, said that due to the "increased unrest" it had relocated a contingent of U.S. forces temporarily, but gave no further details on numbers, Reuters reported.