Yemen's President Hadi orders his forces to 'stand down' after Aden clashes

Yemen's President Abd Rabbo Mansour Hadi on Sunday ordered his forces to cease fire immediately - in the interim capital Aden - after fierce clashes between government forces and southern separatists.

Hadi supporters have called the new fightin an "attempted coup" by the seperatists, who are believed to be backed by the UAE.

The fighting, which killed at least 15 people, threw war-torn Yemen into further chaos and threatened to undermine Hadi's dwindling authority.

Security sources and residents said clashes appeared to have spread to most of the city, with reports of running gun battles.

The call to cease fire came in a communique issued by Yemen's 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.

Earlier, Dagher accused southern separatists of attempting a coup in the interim capital of Aden after they took over the government headquarters during heavy fighting.

"A coup is ongoing here in Aden against legitimacy and the country's unity," he said in a statement.

Security sources told AFP that pro-separatist units - trained and backed by the United Arab Emirates - had taken over the government headquarters in Aden after clashes.

The 15 people killed included three civilians, hospital sources said. Dozens more were wounded.

Saudi and Emirati troops present in Aden did not intervene in the clashes, security sources said.

The fighting erupted after separatist protestors were prevented from entering the city for a rally to demand the government's ouster in Aden, established as its interim base after the Iran-backed Houthis seized control of the capital Sanaa in 2014.

Sunday's rally was called by the Southern Transitional Council, an autonomous body aimed at overseeing self-governance among southern provinces.

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

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

The UN children's agency UNICEF said on Twitter it was "very concerned about the situation in Aden".