Yemeni forces shoot at protesters
Security forces in Yemen have opened fire on anti-government protesters in the capital, killing at least four people, a medical official said.
Mohammed al-Qubati, the director of a field hospital at the main protest site in Sanaa, said at least 37 people were also wounded in the violence.
Witnesses say snipers on rooftops opened fire on the crowd of tens of thousands of protesters marching to call for president Ali Abdullah Saleh's resignation, while pro-Saleh Republican Guard units lobbed tear gas and hunted down protesters.
Republican Guard also clashed near Change Square with the anti-government troops of renegade army general Ali Mohsen al-Ahmar, who defected and joined protests months ago.
Pro-Saleh security forces also tried to disperse a large protest in the southern Yemeni city of Taiz, killing one woman and injuring seven others, medical officials there said.
The latest violence comes a day after security forces fired on a massive rally of some 300,000 people in Sanaa, killing at least 12 protesters dead and wounding some 300.
Saleh is clinging to power in the face of more than nine months of massive street protests, inspired by popular uprisings in Tunisia and Egypt.
Saleh, who has been in office for 33 years, has staunchly refused to quit power.
He has balked at signing a deal that the United States and Saudi Arabia have backed in the hope of providing a smooth transition of power. Under the agreement, Saleh would resign and hand power to his vice president in return for immunity from prosecution.