A miltiary commander was killed and a number of troops were taken hostage when tribesmen raided a republican guard brigade outside Yemen's capital Sana'a on Monday.
Brigadier General Ahmed Abdullah Al-Kulaibi, commander of the 63rd mountain infantry brigade, was murdered in Nihm district where the army has been fighting tribes for months.
The tribesmen raided the brigade after some villages came under heavy artillery attacks that killed and injured tens of innocents.
Clashes erupted at the brigade in which the army and the tribesmen used various weapons.
The army has been fighting tribesmen in Nihm, Arhab and nearby districts on the outskirts of Sana'a for months amid reports tribes have prevented the republican guard from occupying lands to set up camps.
The battles coincided with month-long protests calling for the ouster of the regime faced with deadly crackdown in some Yemeni cities including the capital Sana'a, which has recently witnessed fierce clashes between pro and anti-regime forces.