TRIPOLI, Aug. 30 (Xinhua) -- Libya's UN-backed Prime Minister Fayez al-Serraj on Thursday ordered the military commanders in central and western Libya to stop the ongoing clashes in south of the capital Tripoli.

In an order, Serraj requested the military commanders to "supervise the ceasefire and stop the clashes in southern Tripoli and withdraw all forces in the areas of the clashes."

He also instructed them to "have all of their military camps and sites handed over to their previous military units that were stationed there before the clashes by Sept. 30."

Southern Tripoli has been witnessing violent clashes since Monday between government forces and armed militias, which have so far killed 41 people and injured 123 others.

The reasons for the clashes remained unknown, but there had been growing tensions amid military mobilization in southern Tripoli in the past few days by armed groups from outside and inside the city.

Interior Minister Abdulsalam Ashour told a local TV channel on Monday that a ceasefire agreement in Tripoli had been reached.

However, clashes renewed on Wednesday despite the announcement, a local security source said.