At least three killed in suicide attack on Shi'ites in Yemen

There was no immediate claim of responsibility but the sources said the attack in al Jawf province bore the hallmarks of Sunni Islamist al Qaeda militants, who have carried out similar attacks on northern Yemen's Shi'ite Houthi tribal group in the past.

A Houthi source said the attacker had been heading for a Houthi cultural centre but when stopped at the checkpoint nearby, he detonated the car there. He said two Houthis were killed in the blast.

Al Qaeda militants have a strong presence in Maarib province, next to al Jawf.

At least 24 people have been killed this week in fighting between Shi'ite Muslim fighters and the army and allied Sunni tribesmen. Intense sectarian conflict this year has undermined attempts at national reconciliation in Yemen.

The Houthis - who control much of the northern Saada province bordering Saudi Arabia - also blew up a Sunni religious education centre in Omran province in the north on Friday, local sources said.

Gulf Arab states and the United States are worried about violence in Western-allied Yemen, a neighbour of major oil exporter Saudi Arabia and home to one of al Qaeda's most active wings.

Last month the Yemeni army launched its biggest offensive in nearly two years to try to dislodge al Qaeda militants from southern strongholds, after a wave of attacks on government officials, security forces, foreigners and energy facilities.

(Reporting by Mohammed Ghobari; Writing by Rania El Gamal; Editing by Andrew Roche)