Shiite Houthi rebels blew up the Islamist Islah Party headquarters in Ibb province Saturday, killing four guards, the Associated Press reported, citing Yemeni security officials. Mediators were able to stop the fighting between the two sides and allow those who inside the party HQ to leave, but the rebels later detained 25 people and took them to the office of the provincial governor, AP said.

The rebels also blew up a nearby dispensary that was run by the Islah party, forcing hundreds of people to evacuate, AP reported.

Already in control of Yemen’s capital Sanaa, the rebels indicated Friday they are willing to negotiate the country’s future with President Abed Rabbo Mansour Hadi. Rebel leaders gave Hadi 10 days to form a new government. In response, the United Nations special envoy to Yemen called for a meeting of political parties in the nation.

The rebels took control of Sanaa Sept. 21. They subsequently agreed to a power-sharing arrangement with Yemen’s government. Since then, the country has experienced sectarian violence as anger has grown among Sunnis unhappy with the power-sharing deal.