Updated

Yemeni officials say an intelligence officer has been assassinated in the capital city of Sanaa, in the latest attack against security forces in the country.

Officials say at least 55 military, intelligence and police officers have been killed in Yemen since mid-2011, with most of the assassinations focusing on individuals working in counterterrorism operations.

The officials say Mohammed El-Fil was shot in the head Wednesday by assailants on a motorbike. They spoke on condition of anonymity because they were not authorized to speak to the media.

Last month, two senior officers were assassinated by militants in a drive-by shooting just outside the capital.

Officials believe that Al Qaeda is waging a retaliation campaign against top officials after a military offensive pushed its militants out of their strongholds in southern Yemen.