Sanaa, Oct 20 (IANS): At least 21 Shia Houthi rebels were killed Monday when suspected Al Qaeda militants attacked positions of the group in Yemen.

"The Al Qaeda militants carried out deadly armed attacks against checkpoints manned by Houthi armed men and bombed two Houthi houses in Radda town," an official told Xinhua.

Radda town, in the central province of al-Bayda province, where Al Qaeda terrorists are active, is some 270 km southeast of Yemen's capital Sanaa.

The attack followed sporadic fighting that had started Sunday night, the official said.

The militants fired several rocket-propelled grenades and rockets on Houthi-held sites, causing casualties and heavy damage, the official added.

Local witnesses reported hearing intense gunfire and huge explosions and seeing vehicles mounted with heavy machine guns roaming the town.

On Saturday, at least 13 people were killed in clashes between Shia Houthi militants and Sunni tribes in the central province of Ibb.

The Shia Houthi group, known locally as Ansarullah, advanced to the country's central regions after they took over control of capital Sanaa in late September. However, they are facing growing resistance from Sunni tribes and Al Qaeda militants.