Updated

Security officials say attackers on motorbikes have shot and killed two Yemeni army officers in two separate attacks in the capital, Sanaa.

The officials identified the two victims as Col. Fadhl Mohammed Jaber and Col. Saleem al-Gharbani. They say Tuesday's attacks took place in different parts of Sanaa. The officials spoke on condition of anonymity because they are not authorized to talk to reporters.

Similar attacks have killed several senior Yemeni military and intelligence officials this year.

The government blames al-Qaida and says the militants are waging a retaliation campaign over a military offensive. The offensive was backed by U.S. advisers and managed to push militants out of strongholds in several southern towns.

The U.S. considers Yemen's al-Qaida branch to be the world's most active.