SANA, Yemen — The death toll in four days of clashes between rival Muslim clans in northern Yemen rose to at least 55 on Saturday, one of the clans said, as the Yemeni government tried to broker a cease-fire in a region that is largely outside its control.

Last week in Saada Province, Shiite Houthi rebels began an attack on the town of Damaj, held by Sunni Salafis, the Houthis’ ultraconservative Islamist rivals.

The army initially said a cease-fire had gone into effect on Friday afternoon, but a Salafi spokesman said that clashes had continued Saturday, and that a total of 55 Salafis had been killed by rockets and tank fire.

Yehia Abuesbaa, the leader of a presidential task force seeking to end the fighting in Damaj, said Saturday that a cease-fire was now expected to take effect on Sunday.