Yemeni security forces killed four people after opening fire on protestors in the southern city of Taiz, hospital sources have said.
They said the security forces fired live ammunition at the protestors who want President Ali Abdullah Saleh to step down.
About 200 people were also hurt when the security forces fired tear gas to disperse them.
Seven explosions were heard north of the capital Sanaa, the scene of a week-long fighting between President Saleh's forces and a rival tribe that killed 115 people, residents said.
The explosions were followed by rattles of machine gunfire in the Hasaba district, where Saleh's forces battled members of the powerful Hashed tribe led by Sadeq al-Ahmar in the bloodiest fighting since pro-democracy unrest erupted in January.
