Powerful explosions and artillery were heard in several areas of the capital in the evening, reports news agency AFP. Authorities have urged residents to stay indoors.
The leader of one of the largest armed groups in Tripoli, SSA militia's Abdelghani al-Kikli, is reported to have been killed, reports Libyan TV channel Al-Ahrar and news site Al-Wasat.
The clashes broke out in the southern suburbs between armed groups from Tripoli and rivals from Misrata, a major port city 20 miles east of the capital, according to local media.
The UN mission Unsmil in Libya is urging all parties to cease hostilities.
"Unsmil is concerned about the developing security situation in Tripoli, with intense battles with heavy weapons in densely populated civilian areas", writes the UN mission on X.
Libya has been shaken by violent power struggles between different militias since Muammar Gaddafi was overthrown in a NATO-backed uprising in 2011. The UN-backed government in Tripoli is surrounded and challenged by the military leader Khalifa Haftar in the east whose forces control large landmasses.
Despite relative calm after an agreement on a ceasefire in 2020, clashes sometimes occur between local armed groups over territory and influence.
