Yemen's Shia Houthi rebels and Sunni tribal fighters agreed to a 24-hour ceasefire Saturday.
The truce agreement comes after eight people were killed Friday during violent clashes between tribesmen and Houthis in the province of Ibb, Al Jazeera reported.
According to residents of the area, explosions were heard across the city as the Houthis came under rocket-propelled grenade fire from tribesmen in the surrounding countryside.
The Houthis captured the Sunni majority Red Sea port city of Hudaydah Monday, and on Wednesday, they took control of Dhamar and much of Ibb provinces, security officials said.
Yemen is facing a new reality with the Houthis emerging as a powerful force.
The Houthis, who belong to the Zaidi sect of Shia Islam, have fought the government periodically over more than 10 years in an attempt to win greater autonomy for their strongholds in the northern Yemeni highlands and end what they say is discrimination and marginalisation.
Last month, their fighters entered Sanaa, seizing key government facilities and installations virtually unopposed.