Clashes broke out in Yemen's Red Sea port of Hudaida on Monday, wounding at least 88 people as plainclothes police fired shots and teargas at protesters who responded by hurling stones, witnesses and doctors said.
Residents told Reuters that plainclothes police armed with bats, pistols and stones, attacked thousands of protesters who had marched into the streets outside the square where they have been camped for weeks in demonstrations calling for the end of President Ali Abdullah Saleh's 32-year rule.
"We're appealing for help in medical supplies as we're really suffering from a severe shortage ... the medical situation is really bad," said protester Abdul Jabar Zayed. "We have some friends missing and we think they were arrested, we are still making calculations but no specific number yet."
A first round of clashes hurt 15 people, two were shot and the others were beaten or hit with stones, doctors said, and protesters began to withdraw back to their camp.
But clashes erupted again as riot police fired shots and tear gas at a group of protesters, witnesses said. Protesters responded by marching out of their camp again, this time headed for Hudaida's main thoroughfare, residents told Reuters.
Five people were shot and 68 were beaten or were suffering from teargas inhalation, they said, and clashes were ongoing. Zayed told Reuters that protesters had built a roadblock to try to prevent police from getting closer to the demonstrations.
Tensions have run high in the Arabian Peninsula state, where one in two of its 23 million people owns a gun, as transition talks between the opposition and the government stall.
Protests in Yemen, inspired by uprisings that toppled Egypt and Tunisia's presidents, gather tens of thousands of people almost daily and have now run into their third month.
No breakthrough was reached at a meeting between opposition leaders and foreign ministers of the Gulf Cooperation Council (GCC) in Saudi Arabia on Sunday night. The Gulf Arab states have offered to mediate between the opposition and the government.
But the opposition rejects such talks without guarantees of a quick handover of power and the removal of Saleh.
A GCC statement said on Sunday night the opposition agreed to continue talks with the foreign ministers, and opposition leaders were still in Riyadh on Monday morning. It said the ministers would meet separately with Saleh's representatives.
But a Yemeni government official told Reuters there was no word yet from the GCC on separate talks with Saleh aides.
"We have not yet received an official invitation, we are still waiting," he said.