Officials say at least 55 military, intelligence and police officers have been killed in Yemen since mid-2011. Most of the assassinations focused on individuals working in counterterrorism operations.
The officials say Mohammed El-Fil was shot in the head by assailants on a motorbike. They spoke on condition of anonymity because they were not authorized to speak to reporters.
Last month, two senior officers were assassinated by militants in a drive-by shooting just outside the capital.
Officials believe that al-Qaida is waging a retaliation campaign against top officials after a military offensive pushed its militants out of their strongholds in southern Yemen.
Meanwhile, Yemen's air force, backed by US drones, have struck militant hideouts in several areas of Yemen. The latest airstrike was Wednesday when local tribesmen said an aircraft targeted a vehicle outside of a village on the outskirts of Sanaa, killing two.
Local tribal officials said the airstrike was a rare attack near Sanaa, in the Sanhan district, hometown of the former longtime President Ali Abdullah Saleh.
The officials said the airstrike killed Adnan al-Qadi, a militant previously detained in relation to a U.S. Embassy bombing in Sanaa in 2008.