SANAA, Yemen — Yemeni security officials say gunmen have killed a senior intelligence officer in a drive-by shooting as he emerged from his office in the capital.

The security officials said the killing Monday carries the hallmark of al-Qaida in Yemen, which has been on a revenge campaign following a government crackdown. The officials said Col. Abdullah al-Ashwal is the most senior official to be assassinated in the capital Sanaa.

The officials were speaking on condition of anonymity because they were not authorized to speak to reporters.

Al-Qaida in Yemen, considered the world's most active branch of the terror network, had taken advantage of 18 months of political turmoil to establish its control over swaths of territory in the country's south and center.