By Mohammed Mukhashef and Fawaz Salman
ADEN (Reuters) - Saudi Arabia threw its weight behind Yemen's exiled president on Monday, as United Arab Emirates-backed southern separatists controlling the port of Aden held firm against Riyadh's calls to vacate government sites.
A Saudi-led alliance of Sunni Arab states has fractured after more than four years fighting on behalf of an ousted Yemeni government against the Iran-aligned, Shi'ite-led Houthi movement that controls the capital and most populous areas.
In recent days, the UAE-armed separatists have cast off an alliance with President Abd-Rabbu Mansour Hadi's government and seized much of Aden, which had been his main base.
The UAE, Saudi Arabia's main military ally on the ground for most of the war, has drawn down forces since June.
Saudi Arabia and UAE rulers met in Mecca on Monday, in an apparent effort to stop further damage to their alliance that would boost their common enemy the Houthis.
Saudi Arabia's King Salman bin Abdelaziz and his son, the kingdom's de facto ruler Crown Prince Mohammed bin Salman, discussed the situation with the crown prince of Abu Dhabi, Sheikh Mohammed bin Zayed Al-Nayhan, state-run Saudi TV said.
The Saudi king and crown prince both met Hadi on Sunday, also in Mecca.
The separatist leader, Southern (NYSE:SO) Transitional Council president Aidaroos al-Zubaidi, said his group still supports the coalition against the Houthis and would attend a proposed emergency summit in Saudi Arabia.
But he did not commit to withdrawing his forces from government buildings they seized on Saturday after clashes that killed 40 people including civilians.
SAUDI STILL SUPPORTS HADI GOVERNMENT
Riyadh made clear it still backs the government led by Hadi, who has mainly lived in Saudi Arabia since fleeing Yemen's capital in 2014.
The coalition said it hit a separatist area on Sunday and threatened more attacks if the southerners did not leave.
Residents said fighting has ended since the separatists seized government military bases and surrounded the nearly empty presidential palace in Aden on Saturday.
"It is quiet now but people are still worried. We don't know where matters are heading," Aden resident Adel Mohammed told Reuters on Monday. He said power and water supplies had been restored, but could be disrupted again.
Local media quoted an official at Aden's airport as saying flights had resumed on Sunday.
Zubaidi said the separatists, who want an independent south Yemen, had no choice but to seize Aden following a deadly Houthi missile strike on southern forces earlier this month.
The separatists accuse a party allied to Hadi of being complicit in that strike, which it denies.
"We were left with two options: defend ourselves or surrender to the eradication of our just cause and souls," Zubaidi said in a statement from Aden late on Sunday.
The rift in the coalition complicates U.N. efforts to implement a stalled peace deal in the main port city of Hodeidah to pave the way for broader talks to end the war.
The southern separatists and UAE forces played a major role on the ground in a coalition attempt to seize Hodeidah and cut off supply lines to Houthi-held areas.
The four-and-a-half-year-old war has killed tens of thousands of people and pushed Yemen to the brink of famine.
The UAE has trained thousands of southern fighters who answer to Zubaidi, a militia leader who emerged from relative obscurity in 2015 after helping purge the Houthis from Aden.
Violence has escalated in other parts of Yemen after the Houthis stepped up missile and drone attacks on Saudi cities.
The coalition said it attacked Houthi targets in northern Hajjah province on Sunday that the movement's al-Masirah TV said killed 11 civilians. The alliance said it was investigating civilian deaths in the air strikes.