Heavy fighting between Yemeni government and southern separatist forces left at least 12 people dead in Aden on Sunday before both sides responded to calls for calm by the Saudi-led coalition.
The clashes broke out in the early morning as members of the presidential guard tried to prevent thousands of supporters of the Southern Transitional Council from gathering for a rally in Khour Maksar district.
The rally was being held in defiance of a government ban on public gatherings in the interim capital, imposed on Saturday, to press the STC's demand for president Abdrabu Mansur Hadi to sack his cabinet led by prime minister Ahmed bin Dagher.
The fighting between the presidential guard and southern forces spread to other areas of the district including Hadeed mountain, the government headquarters, Al Aqel roundabout and the Khour Maksar shoreline.
Mr Bin Dagher accused the separatists of staging a coup after their fighters seized the government headquarters.
As the fighting raged, the Saudi-led coalition, which is supporting Mr Hadi's internationally recognised government against Iran-backed Houthi insurgents, issued a call for Yemenis to remain united against the rebels despite differences in views and affiliations.
"The Arab coalition supporting legitimacy in Yemen … calls on all Yemeni political and social components to be calm and to restrain themselves, adhering to the language of calm dialogue," it said in a statement, adding that it was important not to allow those who plotted to divide Yemenis to succeed.
Mr Hadi ordered his forces to cease fire in a communique issued at mid-day through the prime minister to the commanders of government forces.
"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.
It ordered government forces "to return to base", and said all positions taken on Sunday should be vacated by all sides unconditionally.
The fighting subsided by 2pm, although occasional gunfire could still be heard.
The STC promised to abide by the coalition's call for a ceasefire, saying it would continue to press for the dismissal of the cabinet peacefully.
"We trust on the Arab Coalition to intervene with all its power to solve all the troubles caused by the mismanagement of the current government," council spokesman Salem Al Oulaqi said.
Sources in the ministry of health told The National that 12 people had been killed in Sunday's fighting and 23 injured, all of them combatants.
The call for Mr Bin Dagher and his ministers to resign is being led by Aidarous Al Zubaidi, a former governor of Aden province who became head of the STC after being sacked by Mr Hadi in April last year.
Mr Hadi's forces, backed by the Saudi-led coalition that includes the UAE, have recently made steady advances against the Houthi rebels, who still control large parts of Yemen's north including the capital, Sanaa.
Coalition aircraft on Sunday bombed a Houthi military vehicle that was being used as a platform to launch rockets into the city of Hays in Hodeidah province. A 21-second video posted on YouTube by state news agency Wam on Sunday shows satellite images of the Houthi vehicle travelling toward an unidentified building. The vehicle appears to be standing still when a missile strikes, destroying it.
Pro-government forces are fighting their ways towards the rebel-held Hodeidah port on the Red Sea coast, the main entry point for sea cargo.
A coalition-backed offensive to break a rebel siege on the south-western city of Taez has recaptured key areas for Houthis since it was launched on Thursday.