Clashes broke out in the Yemeni city of Aden on Saturday between members of the separatist Southern Transitional Council (STC) and at least four fighters were killed, two security sources said.
Residents reported heavy gunfire in Aden’s central Crater district that houses government headquarters and the central bank.
The city has seen tension between the internationally-recognized government and the STC over control of the south.
The prime minister returned to Aden last week from Saudi Arabia and is residing at the presidential palace in Crater along with other government ministers.
Yemen’s president is based in Riyadh. South Yemen has been paralyzed by the power struggle between the government and the STC, leading to protests in recent months over widespread poverty and poor public services.
They are nominal allies under an Arab-led coalition which has been battling the Iran-backed Houthi movement that ousted the government from the capital Sanaa in late 2014 and now holds most of northern Yemen and main urban centers.
Saudi Arabia mediated a deal aimed at ending the standoff between the government and the STC, including forming a new cabinet that includes separatists, but a planned troop redeployment has yet to take place.