Gunmen on motorbikes shot dead two Yemeni army officers in the country's capital Tuesday, December 25 and clashes between the military and tribal fighters loyal to al-Qaida in a northeastern province killed three soldiers and 11 tribesmen, officials said, according to AP.

The violence came as al-Qaida's offshoot in Yemen, which the United States considers the most dangerous branch of the terror network, released a new video message calling on Yemeni Muslims to join jihad, or holy war, against America.

The two army officers were gunned down in separate parts of the capital, Sanaa, security officials said. The two were identified as Col. Fadhl Mohammed Jaber, who was shot outside his home, and Col. Saleem al-Gharbani, who was killed near a Sanaa military facility.

Similar attacks have killed several senior Yemeni military and intelligence officials this year. The government has blamed al-Qaida, saying the militants are waging a retaliation campaign over a U.S.-backed military offensive last summer that managed to push militants out of strongholds in several southern towns.

Military officials said clashes between the army and a tribe affiliated with al-Qaida in the northeastern province of Marib killed at least 11 tribesmen and three soldiers over the past 24 hours. The officials said a tribal chief, supported by al-Qaida elements and disenchanted over money allegedly owed to him by the government, has been leading the attacks on the army.