Sanaa: Anti-government protesters clashed with police trying to prevent them from marching toward Yemen's presidential palace in Sanaa on Sunday, witnesses said.
Shortly before the clashes, the opposition agreed to enter talks with President Ali Abdullah Saleh, who is keen to avert an Egypt-style revolt in the country, a U.S. ally against al Qaeda.
"The Yemeni people want the fall of the regime," protesters shouted during the demonstration attended by about 1,000 people, before dozens broke off to march to the palace. "A Yemeni revolution after the Egyptian revolution."
Sporadic anti-government protests have gathered momentum in Yemen. Earlier this month, tens of thousands took part in an opposition-led 'Day of Rage' to demand a change of government, inspired by popular protests in Tunisia and Egypt.
Pro- and anti-government protesters have clashed in recent days.
Opposition officials said 10 protesters were detained in Sanaa and 120 were taken into custody overnight in the city of Taiz, where authorities broke up a demonstration on Saturday.
Four people were hurt in the Sanaa clashes, in which police hit protesters with batons and demonstrators threw rocks at police, witnesses said.
Saleh, in power for more than three decades and concerned about unrest in some parts of the Arab world, has said he will step down in 2013 and pledged his son will not take over the reins of government. He invited the opposition for talks.
"The opposition does not reject what came in the invitation by the president and is ready to sign an agreement in no more than a week," said former Foreign Minister Mohammed Basindwa, now an opposition politician, adding that the talks should include Western or Gulf observers.
"Past experience is what has spurred us to request that representatives of the Friends of Yemen (donor countries) be in observance," he said.
Instability in Yemen would present serious political and security risks for Gulf states. The United States relies heavily on Saleh to help combat al Qaeda's Yemen-based arm, which also carries out attacks in neighbouring Saudi Arabia.
Saleh, a shrewd political survivor, has backed out of previous promises to step aside. Analysts say his concessions could be a genuine way to exit gracefully but he may hope to wait out regional unrest and reassert his dominance another day.
The offer of talks, along with other concessions, was his boldest gambit yet to stave off turmoil in Yemen and avert a showdown with protesters in the poverty-stricken state.
Yemen's opposition wants assurances that reforms would be implemented and has demanded better living conditions for Yemenis, about 40 per cent of whom live on less than $2 a day, while a third suffer from chronic hunger.