SANAA - A bomb blast hit an anti-US protest in northern Yemen on Friday, wounding at least 22 people, a rebel group that controls much of the north of the country said.
In a statement, the leader of the Houthi movement - Shi'ite rebels that Yemen's military tried to crush in campaigns in 2004-2009 - said the bombing took place in the province of Saada, on Yemen's northwestern border with Saudi Arabia.
It did not say who it believed carried out the attack.
The region has seen bouts of fighting in recent months between the Houthis and Sunni Muslims espousing puritanical Salafi doctrines influential in Saudi Arabia. The Houthis have accused Riyadh of arming their foes.
The conflict with the Houthis is one of several facing Yemen's new president, Abd-Rabbu Mansour Hadi, as he tries to implement a power transfer backed by Riyadh and Washington.