A strong explosion late Sunday rocked a government administration complex held by Zaidi Shiite rebels in northern Yemen, witnesses said.

The blast happened while leaders of the Shiite rebellion were meeting in the complex at Al-Matamma, a city in Al-Jawf province, northeast of the Sanna, they said.

The complex was in flames and the explosions were heard in several neighbouring villages, witnesses and tribal sources added.

The blast came two days after the signing of a truce by the Shiite rebels and the Islamist Al-Islah party, in a bid to stop the fighting that since March has flared intermittently in the area near the border with Saudi Arabia.

Tribal sources, contacted by AFP from Sanaa, indicated it was a car bomb that claimed several victims without giving a precise number.

Yemen's mountainous northern region is a stronghold of the Zaidis, also known as Huthis, who from 2004 fought six wars with central government forces before signing a truce in February 2010.