ADEN: The Islamic State group claimed a major attack on Yemen’s government bastion of Aden on Sunday which killed at least 15 people, wounded 18 others and sparked a hostage crisis, reports AFP.

IS and its extremist rival Al-Qaeda have taken advantage of the war between Yemen’s Saudi-backed government and the country’s Shiite Huthi rebels, who are allied with Iran, to bolster their presence across much of the south.

While Al-Qaeda in the Arabian Peninsula (AQAP) has for years been the stronger presence in southern Yemen, IS has recently come forward to claim attacks on both the army and the country’s Shiites, whom it considers heretics.

The Islamic State group claimed the Sunday attack on the criminal investigations unit in an online statement released by the IS Aden and Abyan Wilayah, which said clashes were “still ongoing”.

Security officials in the southern province of Aden, where the Yemeni government is based, said an explosives-rigged car blew up outside the investigations unit, killing six officers on the spot along with the driver.

Around 30 gunmen then stormed the unit and freed dozens of detainees from their holding cells, some of whom took up arms to fight alongside the militants, according to a high-ranking official.

The gunmen also took an unknown number of people hostage inside the unit on Sunday afternoon. Two policewomen were killed execution-style by the attackers, the official said.

Earlier on Sunday, Yemeni security sources had said they suspected Al-Qaeda militants were behind the well-coordinated attack. The attack spells an abrupt end to a period of relative calm that has reigned in Aden, where the government of President Abedrabbo Mansour Hadi has been based since it was driven out of the rebel-held capital Sanaa in 2014.

Yemen’s complex war, which pits the Saudi-backed Hadi government against former president Ali Abdullah Saleh and his Huthi rebel allies, has allowed AQAP and IS to flourish in the south of the country.