One night, a Reuters reporter in central Tripoli heard shooting and explosions while the Libyan National Army confronted Prime Minister Fayez Sarraj's government forces around the former international airport and the Ain Zara area.
Italy has also warned France, which has close ties to marshal Khalifa Hafter, to refrain from supporting any faction after diplomats said Paris had blocked an EU statement calling on Hafter to halt the offensive.
"It would be very dangerous if France for economic or commercial reasons prevented the EU initiative to bring peace to Libya," Italian Deputy Prime Minister Matteo Salvini told RTL radio.
Libyan and French officials say France, which has oil assets in eastern Libya, has provided military aid in recent years to Hafter in its eastern stronghold.
Libya has two authorities, one in the east led by Marshal Khalifeh Hafter, which receives support from France and the Gulf states while the other government lies in the west led by Fayez Sarraj, supported by Turkey, Qatar and Italy, which is recognized by the United Nations.