A soldier from the United Arab Emirates stands guard next to a UAE military plane at the airport of Yemen’s southern port city of Aden August 8, 2015.

:: Yemen President Abedrabbo Mansour Hadi on Sunday ordered his forces to cease fire immediately in interim capital Aden after fierce clashes with southern separatists.

The call came in a communique issued by Prime Minister Ahmed bin Dagher to the commanders of government forces in the southern port city.

“Based on instructions from President Hadi, supreme commander of the Yemeni armed forces, and after talks with the Arab coalition… you must order all military units to cease fire immediately,” said the communique seen by AFP.

It ordered government forces “to return to base”, and said all positions taken on Sunday should be vacated by all sides unconditionally.

Coup attempt, accuses PM Dagher

Earlier on Sunday, Prime Minister Dagher had accused southern separatists of attempting a coup in the interim capital of Aden after they took over the government headquarters.

The premier called on the Saudi-led coalition fighting Iran-backed Houthi rebels to intervene, hours after fierce clashes erupted between military units loyal to the government of President Abedrabbo Mansour Hadi and separatist security forces.

At least 15 people were killed in fierce fighting on Sunday in Yemen’s interim capital of Aden, hospital sources said, as separatists took over the government headquarters.

Three civilians were among those killed, medical sources in four hospitals in Aden said.

Apart from those killed, dozens were wounded in the clashes that spread to most of Aden, security sources said.

“A coup is ongoing here in Aden against legitimacy and the country’s unity,” Dagher said in the statement.

Security sources told AFP that pro-separatist units had taken over the government headquarters in Aden after clashes.

The clashes erupted after separatist protestors were prevented from entering Aden where supporters of secessionists were gathering for a rally to demand the ouster of Dagher’s government.

Campaign for Southern secession

The separatists have long campaigned for the secession of southern Yemen, which was an independent country before 1990.

Sunday’s clashes broke out between government troops and security forces loyal to the secessionist movement after protesters tried to enter the southern port city, security sources said.

Medical sources said the fighting wounded seven members of the security forces loyal to the separatists and four civilian supporters of the secessionist movement.

Military units loyal to the government of President Abedrabbo Mansour Hadi were deployed in most areas of Aden amid heightened tensions, the security sources said.

Aden serves as a temporary base for Hadi’s Saudi-backed government as Iran-backed militias took over the capital Sanaa more than three years ago.

A Saudi-led military coalition intervened in 2015 to back Hadi’s government in its war against the Houthi militia.

Ahead of the planned protest, the coalition called for calm and restraint from “all Yemeni political and social components”.

It urged all parties to “adhere to the language of calm dialogue”, according to a statement cited late Saturday by Saudi state news agency SPA.

Sunday’s rally was called for by the South Transition Council, an autonomous body aimed at overseeing self-governance among southern provinces.

The 26-member council, which is not recognized by Hadi’s government, includes the governors of five southern provinces and two cabinet ministers.

Former Aden governor Aidarous al-Zoubeidi formed the council in May after Hadi fired him the previous month.

President Abedrabbo Mansour Hadi ordered his forces to cease fire immediately in interim capital Aden after clashes with southern separatists.