Yemen's opposition has set a two-week deadline for President Ali Abdullah Saleh to step aside, rejecting a Saudi-brokered, Gulf-backed initiative to end the country's political turmoil.
"We have renewed our emphasis on the need for speeding the process of (Saleh) standing down within two weeks. Therefore we will not go to Riyadh," Mohammed al-Mutawakkil, a prominent opposition leader, said on Thursday, referring to the proposed talks in the Saudi capital.
This comes a day after five people were killed in the Yemeni capital Sanaa as forces loyal to a defected army general and pro-government fighters clashed, Al Jazeera's correspondents said.
Two more people were killed on Wednesday in the southern city of Aden in clashes between security forces and anti-regime demonstrators.
The defected general, Ali Mohsen, a kinsman of Saleh who has thrown his weight behind the opposition and whose military units are protecting protesters in Sanaa, has welcomed a mediation proposal by the six-nation Gulf Co-operation Council (GCC) to end the unrest.
But on Tuesday, tens of thousands of Yemenis staged protests against the proposal, with many saying it offers Saleh, in power since 1978, an immunity from prosecution.
Saleh accepts GCC offer
Protesters in Yemen have for months been calling for Saleh to step down over the country's lack of freedoms and extreme poverty. Up to 100 people have been killed in the unrest which shows no sign of subsiding.
The mediation proposal calls on Saleh to transfer power to his deputy, but gives no specific timeframe for him to leave office.
It also includes immunity from prosecution for Saleh and his family.
"The initiative does not clearly mention the immediate departure of the head of the regime and it did not touch on the fate of his relatives who are at the top military and security agencies that continue killing the peaceful protesters," the anti-government Civil Alliance of the Youth Revolution said in a statement.
The alliance, which includes 30 youth groups, said the GCC proposal was an attempt to abort the revolution.
Saleh has accepted the Gulf framework as long as it's carried out "constitutionally," but state media had initially suggested the government would reject it.