One person was killed and 200 wounded when Yemen security forces attacked protesters in the Red Sea city of Hudaida with live and rubber bullets, tear gas, clubs and daggers, a doctor who treated victims said.
The impoverished Arabian Peninsula state has been hit by weeks of protests against the 32-year rule of President Ali Abdullah Saleh. Both pro and anti-government factions appear to have increasingly resorted to violence in the struggle.
The violence erupted following a pro-government demonstration by supporters of the ruling General People's Congress (GPC) party.
A doctor treating protesters in Hudaida said hundreds of security forces and plainclothes police had attacked a sit-in.
"We received around 200 wounded, 10 were hit by gunfire and 40 suffered stab wounds. One died from his gunshot wounds after reaching the hospital," he said.
In the northeastern provincial capital of al-Jawf, three GPC loyalists were wounded in clashes with opposition supporters on the third straight day of attempts by both sides to gain control of government headquarters there, according to a local official.
An activist of the main Islamist opposition al-Islah (Reform) party was shot dead in a gunfight with pro-regime loyalists in al-Jawf on Tuesday, a security official has said.
On Monday, 20 people demanding Saleh's resignation were injured when they assaulted the government headquarters in al-Jawf, northeast of Sanaa, an official said.
Security forces and pro-regime loyalists, who were guarding the building and opened fire in an effort to break up the protest, were wounded by stones hurled by the protesters.
On February 22, al-Jawf, a stronghold of the Zaidi rebels, also known as Houthis, joined anti-Saleh protests that erupted across the poverty-striken country in January and gained momentum last month.
The Zaidis fought six wars with Saleh's government forces from 2004 before signing a truce in February 2010.
Donor meet cancelled
The United States, which has long seen Saleh as a bulwark against an aggressive al-Qaeda wing based in Yemen, has condemned the bloodshed and backed the right to peaceful protest. It says only dialogue can end the crisis.
Protesters, frustrated by rampant corruption and soaring unemployment, have been increasingly strident in their demand that Saleh step down. Some 40 percent of Yemen's 23 million people live on $2 a day or less and a third face chronic hunger.
As widespread protests continue despite rising violence and Saleh's promises of reform, Yemen delayed a meeting with a group of Western and Gulf Arab donors, known as "Friends of Yemen", in Riyadh later this month, state news agency Saba said.
"Yemen proposed delaying the group's coming meeting to give a chance for more preparation and coordination and will announce a new date soon," Saba said.
In further violence on Wednesday, a leading activist in Taiz said plainclothes police targeted and beat women at a rally in the city, 200 km (125 miles) south of capital Sanaa, where tens of thousands have camped out for weeks. At least eleven there were wounded, Bushra al-Maqtari said.
Even before protests, Yemen had been teetering on the brink of failed statehood. Saleh's cash strapped government has been struggling to cement a truce with Shiite rebels in the north and quell a separatist rebellion in the once independent south