Sanaa, Feb 13 (IANS): Unidentified gunmen shot dead an air force colonel as he was leaving a mosque after Friday prayers in Yemen's southern province of Lahj, a security official told Xinhua.

"Air force Col. Mahmoud Naqeeb, who participated in several counter-terrorism operations against Al Qaeda strongholds in the country's southern regions, was assassinated by gunmen in Lahj province," Xinhua news agency quoted a security official as saying on condition of anonymity.

"Two gunmen on a motorbike opened fire at the colonel when he left Friday prayers at a local mosque in the provincial capital," the security source said.

The security source added that the motive for the assassination was not immediately clear, and held the Al Qaeda offshoot in the country responsible for the attack.

Yemen, an impoverished Arab country, has been gripped by one of the most active regional Al Qaeda insurgencies in the Middle East.

Al-Qaeda in the Arabian Peninsula (AQAP), which emerged in January 2009 and also known locally as Ansar al-Sharia, had claimed responsibility for a number of attacks on Yemen's army and government institutions.