ADEN - Al-Qaeda fighters forced pro-government forces out of a strategic town in southern Yemen on Wednesday after clashes that left at least 15 people dead, officials said.

The jihadists briefly took control of Jaar in southern Abyan province, which a military source described as a key link between main southern city Aden and Mukalla, the Qaeda-held capital of southeastern Hadramawt province.

A government official in the town told AFP that the jihadists withdrew hours later after "carrying out an operation" to kill Ali al-Sayed, a commander of the pro-government "Popular Resistance" forces who have been fighting Iran-backed rebels. Sayed and 10 of his forces were killed in the clashes, the official said.

Jaar is a stronghold of the so-called Popular Resistance, which has been battling the Shiite Huthi rebels and their allies, includes Sunni Islamists, tribesmen, loyalist soldiers and southern separatists. Four Al-Qaeda fighters were killed in the clashes, the government official said.

"Jaar is now free from Al-Qaeda and Popular Resistance committees," the source said, adding that the jihadists withdrew from the town towards provincial capital Zinjibar, where they already control government offices.

Seizing Jaar could secure the link between the jihadists' Mukalla stronghold and Aden, which houses the internationally-recognised government's temporary headquarters, according to the military source. It would allow the militants to send reinforcements from Mukalla to Aden via Jaar. Iran-backed rebels have been battling pro-government forces in Yemen for months, and the loyalists in July launched operations to retake five southern provinces, including Abyan and Aden, from the insurgents.

But Islamist militants, including Al-Qaeda and the Islamic State group, appear to have gained ground in and around Aden, where jihadists are now visibly present. As they entered Jaar, the jihadists blew up the main Popular Resistance headquarters and hunted down pro-government fighters, the majority of which fled the town, witnesses said. Locals told AFP by telephone that a militant leader announced over loudspeaker from the town's Grand Mosque that Al-Qaeda in the Arabian Peninsula (AQAP) had full control of "the emirate of Jaar" and that residents were now "safe" and life could go on "normally".

But hours later, no Al-Qaeda militants could be seen in Jaar, witnesses said, adding that eight armoured vehicles the fighters deployed during the clashes later withdrew to Zinjibar.

A resident who said he had spoken to the jihadists told AFP that AQAP has a list of names of pro-government forces that they plan to "liquidate" and that they planned to "leave Jaar to its own people".

AQAP, already active in the south and southeast, has exploited the unrest in Yemen, where a Saudi-led coalition has been pounding rebels since March.

The militants have imposed a strict version of Islamic law in Mukalla, which they seized in April.

Last month, radical Islamist gunmen entered a faculty at Aden university, forcing students to leave the campus, and locked down the faculty's main gate, according to witnesses.

They said the gunmen closed the faculty after they had threatened to use force against students if they did not observe segregation of the sexes on campus. The rebels last year seized the capital Sanaa, and their expansion into central and southern areas forced President Abedrabbo Mansour Hadi to flee to Saudi Arabia before later returning to Aden. The United States considers AQAP to be the most dangerous affiliate of the Al-Qaeda jihadist network. It seized Zinjibar and other parts of Abyan in 2011, where members remained before being defeated by local army-backed militias a year later.

Moreover, long-delayed peace talks for Yemen are expected to finally open in Geneva in mid-December, the British ambassador to the United Nations said Wednesday. Yemen forces backed by air power from a Saudi-led coalition have been battling Huthi Shiite rebels who captured the capital Sanaa over a year ago.

British Ambassador Matthew Rycroft told reporters that the UN-brokered talks "will probably happen in Geneva in the middle of the month." "We strongly support those because that is the route to ending the conflict," he said.

More than 5,700 people have been killed in Yemen since the Saudi-led air campaign began in March, according to the United Nations.

The conflict took a worrisome turn this week when Al-Qaeda fighters battled pro-government forces in Jaar in southern Yemen, briefly taking control of the town.

Rycroft said the threat from Al-Qaeda in the Arabian Peninsula (AQAP) highlighted the need to find an urgent resolution to the Yemen crisis. UN envoy Ismail Ould Cheikh Ahmed has been holding talks for weeks with all sides to try to launch peace talks, but no date has been announced for the formal negotiations. An attempt in June to bring the Yemeni parties together at a negotiating table failed. Yemen's humanitarian crisis has been identified by the United Nations as one of the world's worst, with 80 percent of the country's population on the brink of famine.