Suspected al-Qaeda fighters attacked the intelligence services headquarters in the center of this southern port city Saturday, killing at least 14 Yemeni soldiers and security guards, Yemeni security officials said.

The morning attack highlighted the continuing ability of al-Qaeda in the Arabian Peninsula, the terrorist network’s Yemen affiliate, to strike high-profile military and security targets even after being pushed out of several southern towns this summer by a U.S.-backed Yemeni army offensive.

The well-planned operation in Aden, launched on the last day of the Muslim holy month of Ramadan, began when the extremists detonated a car bomb next to the intelligence headquarters, according to the Defense Ministry. They then attacked the building with rocket-propelled grenades and gunfire, shattering windows and setting it on fire, before fleeing, the ministry said on its Web site.

The death toll is expected to rise, as many bodies were still buried under the rubble, the ministry added. At least seven other soldiers and security guards were injured.

Saturday’s assault appeared to be the latest in a string of deadly attacks orchestrated by al-Qaeda in the Arabian Peninsula, or AQAP, since May, when the militant group targeted a military parade rehearsal in the capital, Sanaa, killing at least 90 people. Since then, members of the group have attacked a police academy in Sanaa, assassinated a senior commander in southern Yemen and tried to kill the leader of a pro-government citizen’s force that is fighting to defeat it.

Sanaa, Yemen (The Washington Post/-)

The Obama administration considers AQAP — which has tried to stage attacks on U.S. territory several times since 2009 — al-Qaeda’s most ambitious affiliate and a significant threat to the United States and its allies, particularly neighboring Saudi Arabia, the world’s biggest oil exporter. This year, the administration has escalated a campaign of drone strikes across southern Yemen in an effort to weaken the group.

Last year, the militants seized advantage of Yemen’s political turmoil and took control of several towns in Abyan province, adjacent to Aden, including the provincial capital of Zinjibar. After President Ali Abdullah Saleh stepped down from power in February, the new government launched a major offensive against the militants with the help of the United States, driving them into the mountains and villages under the protection of sympathetic tribes.

In a separate development late Saturday, a Yemeni southern secessionist leader told the Reuters news service that he had been released from captivity, three days after gunmen took him hostage when he arrived in Aden on Wednesday. Ahmed Abdullah al-Hassani had traveled from Britain, where he lived in exile, to meet with other leaders of the south’s secessionist movement, which has long complained about discrimination and inequalities in sharing of resources by Yemen’s northern rulers.

North Yemen and South Yemen were unified in 1990 but have had a tense relationship since then, including engaging in a brief civil war in 1994 that was won by the north.