Yemen ceasefire deal violated a day after coming into force: official SANAA (Reuters) - A government-brokered ceasefire intended to halt days of clashes in northern Yemen between Shi'ite and Sunni Muslim fighters has been violated a day after it came into force, an official said on Monday. The fighting has killed at least 100 people since it began on October 30 when Shi'ite Houthis, who control much of Saada province on the border with Saudi Arabia, accused Salafi rivals in the town of Damaj of recruiting thousands of foreign fighters to prepare to attack them. The ceasefire came into effect on Sunday. "The Shi'ite Houthi group violated the ceasefire agreement with the Salafists in the northern province of Saada," said a Yemeni government official on Monday. Yehia Abuesbaa, head of a presidential committee tasked with ending the fighting, said inspectors were sent to the conflict area to investigate who had broken the ceasefire. "After we arrived, accompanied by the army, to the affected area, we were surprised that gunfire was being fired at us," he said. The Houthis told us not to let inspectors down in the other party's area. A Houthi official then held us for some time and that's why we returned to the city of Saada," Abuesbaa said. Sectarian rivalry in Damaj is hampering reconciliation efforts in Yemen, a neighbor of top oil exporter Saudi Arabia and home to one of al Qaeda's most active wings. An attempt to broker a ceasefire last week collapsed but the lull in fighting enabled Red Cross officials to evacuate nearly 70 people from Damaj. The turmoil on several fronts in Yemen has alarmed the United States which has stepped up aid and military support for the government as part of its global fight against Islamist militants. Reporting by Mohammed Ghobari; Editing by Janet Lawrence