At least 33 people were killed and wounded on Wednesday in the central Yemeni city of Ibb, 193 kilometers (119 miles) south of the capital, Sana'a, after a suicide attacker detonated an explosive belt at a cultural center where Shiite Houthis were preparing to celebrate the birthday of the Prophet Muhammed.
The exact number of casualties was not immediately clear, but medics have warned that the death toll was likely to rise.
Security sources said another bomb was discovered at the entrance to the cultural center.
The regional governor, Yanya al-Aryani, was reportedly among the wounded.
The Houthis have seized large swathes of territory in Yemen this year, including most of Sana'a. Their opponents view them as acting on behalf of Shiite Iran, but they themselves deny this.
However, their land grab has angered local Sunni tribes, and they have also been the target of a number of attacks by Yeman's powerful local al Qaeda affiliate.
Yemen has been in a state of turmoil since 2011, when mass protests broke out against former President Ali Abdullah Saleh. Saleh, who narrowly escaped death in a bomb attack in June 2011, was forced to step down in 2012.
The country is struggling to cope with security threats posed by al Qaeda, an unruly military, pirates in the Gulf of Aden and the Houthi rebels.
tj/pfd (AP, dpa, AFP)