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.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-story 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 defense ministry.