At least 40 soldiers and 35 opposition militants were killed in fierce battles in Yemen's northeastern province of Sanaa on Thursday when the latter attempted to raid a military base of the Republican Guards, a military official told Xinhua.

"As many as 40 soldiers of the Republican Guards stationed in Samaa military base in Arhab district were killed when they confronted an attack by armed tribesmen of the opposition coalition Joint Meeting Parties (JMP), who managed to control some eastern parts of the most powerful military base earlier Thursday and held 50 soldiers as hostages," the official said, requesting anonymity.

"The soldiers backed with Yemeni warplanes, however, forced the tribal militants out of the base, killing up to 35 members of the opposition armed group," he added.

Earlier, the ruling party's website reported that Republican Guards repelled an attack by the opposition-backed armed tribesmen and al-Qaida militants that targeted their Samaa military base, killing 30 militants.

The Defense Ministry said in a statement that the JMP armed militants were backed by heavy forces and weapons provided by defected First Armored Division, which was commanded by dissident Major General Ali Mohsen al-Ahmar, the half brother of President Ali Abdullah Saleh.

The ministry accused the opposition JMP of seeking to occupy the military base, seize Sanaa International Airport and set besiege on the northern and eastern entrances of Sanaa.

Saleh's elite Republican Guards is run by Saleh's elder son Ahmed Ali Abdullah Saleh.

Tribal sources said warplanes were still striking hideouts of the militants in several villages in Arhab.

Arhab, about 60 km northeast of the capital Sanaa, has witnessed sporadic clashes between Republican Guards and opposition-backed armed tribesmen since late May that left dozens of the two sides dead and forced hundreds of families to flee the area.