Security Belt forces seize all government camps in port city and are surrounding the presidential palace, officials say.

Separatists in southern Yemen have seized all government military camps in the port city of Aden, officials said, amid heavy fighting that has killed and wounded scores of people.
The separatists, who are aligned with the United Arab Emirates- backed Southern Transitional Council, took control of the Fourth Brigade and Tarek military camps from forces loyal to Yemen's internationally recognised government on Saturday, according to government officials and local sources.
"It is all over, the [Southern Transitional Council] forces are in control of all the military camps," an official in President Abd-Rabbu Mansour Hadi's government told Reuters news agency.
The separatists, known as the Security Belt forces, also surrounded the all-but empty presidential palace in Aden, the city temporarily hosting Hadi's government, theeuters and AFP news agencies said. Hadi is based in Saudi Arabia's capital, Riyadh.
The fighters also took over the house of Interior Minister Ahmed al-Mayssari after he was evacuated with the help of coalition forces, government officials told Reuters. 
The Yemeni government accused the STC of staging a coup.
"What is happening in the temporary [government] capital of Aden by the Southern Transitional Council is a coup against institutions of the internationally recognised government," the foreign ministry said in a Twitter post. 
The combatants are nominal allies in the Saudi-led coalition that has been battling Houthi rebels in northern and western Yemen since March 2015, but they have rival agendas for the country's future. 
The Associated Press news agency, citing government officials, said at least 45 people were killed in the clashes at the Fourth Brigade camp on Saturday. The DPA news agency, citing a local medical official, said 30 people were killed.

'State of war'

Doctors Without Borders (MSF), in a statement on Saturday, said the city was "in a state of war" and has ground to a halt because of the fighting.
The humanitarian group said it has treated 119 people in less than 24 hours.
"Most of the wounded are civilians trapped by the fighting and probably victims of mortar fire or stray bullets. Yesterday we treated a woman who had a bullet wound and she was eight months pregnant. At least five people were dead on arrival at the hospital, one of them a child," said Caroline Seguin, MSF’s head of programmes in Yemen.
"The city's a battlefield. We can hear the sound of heavy weapon fire and tanks are moving around the streets," she said.
The violence in Aden highlights a rift within the alliance and threatens to open a new front in Yemen's five year-war, which has killed tens of thousands of people and pushed the impoverished country to the brink of famine.
The clashes between the two groups began on Wednesday when forces loyal to the STC attempted to break into the presidential palace in Aden after a call from ex-cabinet minister Hani Bin Braik, who serves as the council's deputy head, to "topple" Hadi's government. 
Al Jazeera's Mohammed al-Attab, reporting from Yemen's capital, Sanaa, said the Security Belt forces "have taken over the most important military camps and government institutions. This is indication that the separatist council is heading towards taking over the whole city". 
It was the recent withdrawal of UAE forces from Aden that "encouraged [separatists] to take over the city", al-Attab said, referring to Abu Dhabi's decision in July to pull out thousands of troops from Yemen.
A Houthi-claimed attack on a military parade that killed 36 people, including a senior Security Belt commander, also inflamed tensions between the separatists and the government forces, our correspondent said. 
The latter accused an Islamist party allied to Hadi of complicity in the attack. 
"The Security Belt viewed the attack on the military parade with suspicion as they feel there are many parties involved seeking to destroy and weaken their forces," our correspondent said.
"Today, they have achieved many of their goals by taking over all of the camps," he added. "This is another failure for the Saudi-led coalition."
Members of UAE-backed southern Yemeni separatist forces stand by a tank during clashes with government forces in Aden
Members of UAE-backed southern Yemeni separatist forces stand by a tank during clashes with government forces in Aden [Fawaz Salman/Reuters]

'Deep concern'

Southern Yemen was an independent state until 1990 and the north is widely perceived to have imposed unification by force. 
Relations between Hadi and the UAE have been tense amid allegations the Emiratis have offered patronage to southern Yemeni politicians campaigning for secession, as well as what Hadi perceives as UAE violations of his country's sovereignty.
On Thursday, Hadi's government urged Saudi Arabia and the UAE to put pressure on the Security Belt to avoid a military escalation in Aden.
UAE Foreign Minister Abdullah bin Zayed Al-Nahyan expressed "deep concern" on Saturday over the violence in Aden and called for a "de-escalation".
"Sheikh Abdullah called for a responsible and serious dialogue to end the differences and work on unity in this delicate phase while maintaining security and stability," the official Emirati news agency WAM reported.
He said the UAE was "exerting all efforts to calm and de-escalate the situation in Aden", saying the two camps should focus their efforts on fighting the Houthis not each other.
Sheikh Abdullah also called on the United Nation's envoy to Yemen, Martin Griffiths, "to make all possible efforts to end the escalation in Aden", the statement added.
Antonio Guterres, the UN secretary-general, called for an end to hostilities in Aden.
Expressing concern over the clashes in the vicinity of the presidential palace and the international airport in Aden, Guterres on Saturday urged "the parties to engage in an inclusive dialogue to resolve their differences and address the legitimate concerns of all Yemenis".
The UN is trying to de-escalate tensions countrywide as it tries to implement a peace deal in the main port city of Hodeidah further to the north, to pave the way for wider political talks to end the war.
Separately, the Houthis' Al-Masirah TV quoted a military spokesman as saying the group had launched a drone attack against Saudi Arabia's civilian Abha airport, targeting the fuel depot and control tower.
Saudi-owned al-Arabiya TV said air traffic at the airport was normal.
The Houthis, who have stepped up cross-border missile and drone strikes on Saudi Arabia, control Sanaa, Hodeidah and other major urban centres while Hadi's government holds Aden and a string of western coastal towns.