At least 14 military personnel die in al Qaeda linked attack on intelligence HQ in Aden
Suspected al Qaeda-linked militants killed at least 14 Yemeni soldiers and security guards on Saturday in a car bomb and grenade attack on the intelligence service headquarters in the southern port city of Aden.
More bodies were believed buried under the rubble of the building, part of which was levelled in the assault, the defence ministry said. At least seven people were wounded.
The United States has been pouring aid into Yemen to stem the threat of attacks from al Qaeda in the Arabian Peninsula (AQAP) and to try to prevent any spillover of violence into neighbouring Saudi Arabia, the world's top oil exporter.
Last year, a US-backed offensive drove al Qaeda offshoot Ansar al-Sharia (Partisans of Islamic Law) from cities it had seized in an uprising against former president Ali Abdullah Saleh.
But Islamist militants have carried out a number of suicide bombings on high-profile military and security targets since June, exposing the government's vulnerability.
On Saturday, witnesses said militants drove up to a building owned by Yemen's state television broadcaster and blew up a military vehicle guarding it outside.
They then moved on to the three-storey intelligence base nearby and opened fire with automatic weapons and rocket-propelled grenades.
The attackers also detonated a car bomb next to the building, destroying part of it, said the defence ministry.
The ministry said the attack killed 14 people and wounded seven - all of them members of the intelligence service and the Central Security forces.
A security source and medics said 18 people died.
Resident Ashraf Ali Ahmed, said a loud explosion shook the area, followed by smaller blasts.
A local security source said the attack carried the hallmarks of al Qaeda. "The operation seemed to have been well planned," the source said.
In July, militants attacked a police academy in Sanaa, assassinating the commander of the southern region.
Washington has responded to the violence by stepping up its drone strikes on AQAP, which was behind several failed attacks on the United States, including an attempt to blow up an airliner over Detroit on Christmas Day in 2009.