Libyan Prime Minister Fayez Sarraj speaks to the media. File photo

Officials from Libya's two rival governments said fighting erupted on Sunday as the country's east-based forces advanced toward the strategic western city of Misrata, further eroding a crumbling cease-fire agreement brokered earlier this month.

The clashes came just hours after the United Nations decried "continued blatant violations” of an arms embargo on Libya by several unspecified countries. The violations fly in the face of recent pledges to respect the embargo made by world powers at an international conference in Berlin last week.

Libyan military commander Khalifa Haftar arrives at a meeting. File photo

Libya is divided between rival governments based in its east and west, each supported by various armed militias and foreign backers.

The weak but UN-recognised government is based in the capital, Tripoli, and led by Prime Minister Fayez Sarraj. Rival forces based in the east and loyal to military commander Khalifa Haftar forces were advancing some 120 kilometres (around 75 miles) east of Misrata, near the town of Abugrein, according to the media office of militias allied with the Tripoli government. It said clashes were still taking place in the outskirts of Abugrein.

A spokesman for forces allied with the Tripoli government, Mohamed Gnounou, said in a statement posted online that Haftar’s repeated violations made the cease-fire "useless.”

An official with Haftar's forces said they have wrested control of two towns, Qaddaheya and Wadi Zamzam, on their way to Abugrein. The official spoke on condition of anonymity in line with regulations.

Associated Press