SANAA// Dozens of people have been killed or wounded in fighting between anti-government tribesmen and Republican Guard forces loyal to the Yemeni president, Ali Abdullah Saleh.
The clashes began on Saturday, with tribesmen overrunning a Republican Guard base.
Tribal officials said tribesmen in Nehm district, 70 kilometres north of Sanaa, took control of the base and fired rockets on army brigades.
The Republican Guard are commanded by Mr Saleh's son, Ahmad.
A tribal leader said at least 12 tribesmen were killed and more than 40 wounded, mostly by landmines planted around the base. About 400 soldiers were captured, along with a cache of weapons.
Warplanes launched strikes on the base yesterday, while tribalmen responded with anti-aircraft weapons.
The strikes hit villages in the region and badly damaged them, said residents.
No precise figures were available for the casualties among the soldiers.
But the ruling party website said the military repulsed the attack and inflicted heavy losses on the attackers.
It blamed Ali Mohsen Al Ahmar, commander of the First Armoured Division, who defected from the Yemeni military, and the Islamist Islah party for the attacks.
The clashes followed the killing of Colonel Abdulsalam Al Sufyani, the head of operations of the Third Brigade of the Republican Guard based in Arhab, a defence ministry website said on Sunday.
Mr Saleh warned of "painful and decisive response if attacks on the Republican Guard forces" continued.