The Yemeni opposition called on the United Nations on Thursday to force President Ali Abdullah Saleh to step down unconditionally, rejecting his request for international guarantees.
The opposition Common Forum dismissed as a sham Saleh's announcement on Wednesday that he was ready to sign a Gulf-brokered deal for him to quit office in return for a promise of immunity from prosecution if it was backed up by European and US guarantees.
"It is clear he absolutely refuses to resign and hand power to his vice president," Mohammed Qahtan, the spokesman for the opposition coalition Common Forum told AFP.
"Unfortunately, his statements are in effect a declaration of war," he added.
Thousands of pro-democracy activists who have for months been camped out at their base in the Sanaa's Change Square also rejected Saleh's request for guarantees.
"No immunity, no guarantees, Saleh and his aides will be judged," chanted thousands of demonstrators as they marched Thursday in the capital.
Thousands of Saleh supporters also marched in the capital but were intercepted by government troops, who managed to prevent an confrontation between the two groups, an AFP correspondent at the scene said.
Thursdays protests, in contrast to recent days and weeks of violent government crackdowns, ended peacefully.
Since calls for an end to Saleh's 33-year rule erupted in January, the president has made repeated pledges to sign the deal brokered by his impoverished nation's wealthy Gulf neighbours only to backtrack.
Saleh's latest statement was yet another diversion, Qahtan said, noting that the Gulf Cooperation Council plan already included both an immunity clause for Saleh and his family, and a timetable for the transfer of power.
In a sign Washington is losing patience with Saleh's stalling tactics, a State Department spokesman said Wednesday more guarantees were unnecessary, and urged Saleh to sign the GCC initiative "without further delay."
Qahtan said the time had come for decisive UN action.
"Ali Saleh is not going to willingly give up power... not now, not in 2013, and not in 2020," Qahtan told AFP.
"We call on the UN to adopt a binding resolution that demands Saleh's resignation and clearly supports the revolutionaries and the armies that support them," he added.
In the coming days, the UN Security Council is expected to vote on a resolution condemning the escalating violence between the protesters and Saleh's loyalists.
But the resolution will not threaten sanctions or explicitly call on Saleh to step down, according to a text of the draft seen by AFP.
At least 23 civilian demonstrators and two dissident soldiers have been killed since Saturday as Saleh's opponents have repeatedly attempted to march on loyalist-held parts of the capital in a bid to bring the nine-month-old protests to a head.