SANAA, Yemen - Yemeni President Ali Abdullah Saleh has agreed to step down within weeks in return for immunity from prosecution, but protesters said they would keep up their demonstrations until he went.

Protesters, who have taken to the streets in the tens of thousands demanding an end to Saleh's nearly 33-year rule, are worried the plan could be a maneuver between the president and official opposition parties to share power.

The handover plan was drawn up by the Gulf Cooperation Council and endorsed by the official opposition coalition known as the Joint Meeting Parties.

"We won't stop protesting and we will continue to escalate. This initiative doesn't have anything to do with us," said Mohammed Sultan, a protester in the capital Sanaa. "It has to do with the Joint Meeting Parties that accepted the offer."

In the square in Sanaa where protesters have camped out for weeks, protesters shouted: "No negotiation, no dialogue - resign or flee."

"There is still one month until the president resigns and we expect him at any moment to change his mind," said activist Mohammed Sharafi. "We will not leave ... until Saleh goes and we achieve our goals of setting up a modern, federal state."

Some worry the 30-day period Saleh has until resignation - and it is not yet clear when that period starts - offers a window of opportunity to spark clashes that could derail the transition plan.

Also on Sunday, fresh clashes erupted between armed tribesmen and Republican Guard forces in Yemen's southern province of Lahij on Sunday, killing five people, four of them soldiers.

"Saleh's sons, who are military leaders, as well as tribal leaders stand to lose power under this agreement," said Ali Seif Hassan, a Yemeni political analyst.

"If there is no civil war, they will be the losers ... but if there was, they would gain because they would be the ones to lead the fight."

Ibrahim al-Ba'adani, an opposition activist in the city of Ibb, said he was "surprised" that the formal opposition had accepted the principle of immunity for Saleh.

Reuters