Intense fighting erupted in the Libyan capital, Tripoli, overnight and continued on Saturday, killing at least seven people and injuring over 31, Al Jazeera reported.

Rival factions exchanged heavy gunfire and the sounds of several loud blasts ricocheted around Tripoli.

The clashes took place in Tripoli's city center after one of the capital's strongest groups assaulted the base of a rival force, witnesses said, leading to hours of shooting that terrified locals and raised fears of an escalation.

Numerous images on social media purported to show cars burnt-out in the fighting and bullet-riddled buildings.

The government mandated by the House of Representatives denies the statement of the Government of National Unity regarding the rejection of any negotiations with it, saying it welcomed all local and international initiatives to resolve the crisis, Libya panorama channel reported.

The United Nations in Libya expressed its deep concern at the ongoing armed clashes, including indiscriminate shelling with medium and heavy weapons in civilian populated neighborhoods of Tripoli, causing civilian casualties and damage to civilian facilities including hospitals.

Large armed factions backing each side in Libya's political dispute have repeatedly mobilized around Tripoli in recent weeks, with convoys of military vehicles moving around the city and threatening use of force to obtain their goals.

(With input from agencies)