"Violent clashes raged for several hours between military forces and supporters of Zaidi preacher Badreddin al-Huti," a military official at the scene told AFP, contacted by telephone from Sanaa.
Witnesses said the fighting broke out as soldiers tried to seize control of a rebel stronghold to the north of Saada, in a mountainous region close to the Saudi border.
"The clashes led to the deaths of 15 of al-Huti's supporters and one soldier. Six other troops were wounded, and one of them, a commander, was said to be seriously hurt," the military official said.
Tribal sources said four more soldiers were killed and six wounded in an ambush at Hafr Sufian, on the road from Saada to the capital. The soldiers were attacked as they sat in a restaurant having breakfast.