SANAA (Reuters) - Yemeni security forces and pro-government gunmen killed 10 people and wounded around 50 others when they opened fire at a protest in Sanaa after Muslim prayers on Friday, medical sources and witnesses told Reuters.
A doctor said the death toll may rise further.
"Ten people were killed and the number is expected to increase because there are 30 people in a critical condition," said the doctor, at a field hospital at the protest camp at Sanaa University.
Gunfire broke out when security forces tried to prevent anti-government worshippers from marching after prayers near the protest base at Sanaa University, and plumes of smoke from burning tires filled the air.
Tens of thousands of Yemenis had gathered in Sanaa for competing prayers and protests as businessmen floated a proposal to end a standoff between President Ali Abdullah Saleh and protesters demanding he step down immediately.
Yemen, next door to top oil exporter Saudi Arabia, has been rocked by weeks of demonstrations that have undermined Saleh's grip on power. Tens of thousands of protesters were also gathered in cities across Yemen, from the southern port city of Aden to Hodeida in the west.
The United States, which has long seen Saleh as a bulwark against a dynamic al Qaeda wing based in Yemen, has condemned the bloodshed and backed the right for peaceful protest, but has insisted only dialogue can end the political crisis.
Saleh has promised to step down in 2013 and offered a new constitution giving more powers to parliament, but he has refused his critics' main demand to quit immediately.
A string of Saleh's allies have recently defected to the protesters, who are frustrated by rampant corruption and soaring unemployment. Some 40 percent of the population live on $2 a day or less in Yemen, and a third face chronic hunger.
(Reporting by Mohammed Ghobari and Mohamed Sudam; Writing by Cynthia Johnston, editing by Diana Abdallah)