The Sharia Supporters, the offshoot of Yemen Al-Qaida, claimed responsibility for suicide bombings targeting Houti followers in Saada and Jawf provinces in north Yemen on Friday.
Almasdar Online quoted a statement by the group, which has been fighting the army since it seized key towns in the south last year, that a suicide bomber infiltrated into a Houthi rally early Friday and detonated an explosive belt.
"The bombing killed about twenty Houthi followers and wounded tens others," the statement said, according to the website.
However, the Houthi Group said earlier the bomber failed to target the rally, which is organized a week, adding, "the bomber blew himself up away from the rally and none was hurt".
In Jawf, another suicide bomber rammed an explosives-laden car into a school where many Houthis gathered killing at least 14 including passersby and injuring others.
The militant group said it was behind the bombing, though the leader of the Houthi Group said the attacks were orchestrated by the US intelligence systems to further meddle in Yemen's internal affairs. "The US is responsible for aggressive attacks against us, but we will not allow anyone to drag us into an elusive war due to US acts," Abdul Malik Al-Houthi was quoted as saying.
Al-Qaida said the explosives-laden car in Jawf targeted a weekly meeting by the Houthi Group and a key Shiite preacher was among the victims, the website said.
Two years ago, Al-Qaida targeted a Houthi convoy killing and injuring tens of Shiites.
The Yemeni army has fought the Houthi Group six times.
Experts said Yemen has the most dangerous, extremist groups in the region: the Houthi and Al-Qaida.
Meantime, the Yemeni army has been advancing on Al-Qaida militants in the southern province of Abyan, killing and injuring hundreds of them including senior leaders.
More recently, the army has stepped up the offensive to retake key towns including the capital Zinjibar, which were seized last year.