Yemen's embattled president on Thursday proposed a new constitution guaranteeing the independence of the parliament and judiciary, but thousands of unsatisfied protesters poured into the streets to demand his ouster.
Opposition leaders promptly rejected President Ali Abdullah Saleh's offer and called for mass demonstrations Friday, marking a month since the protests began.
The demonstrators have set up protest camps in the capital and the cities of Aden and Taiz, saying they won't leave until U.S.-backed Saleh resigns.
Saleh, an ally in the Obama's administration's fight against al-Qaida, has been making a series of concessions to try to head off the protests, seen as one of the most serious threats to an Arab government since popular revolutions toppled regimes in Tunisia and Egypt.
Saleh told thousands of supporters gathered at a stadium in Sanaa that a new constitution would be drafted by the end of year establishing the separation of legislative and executive powers. The president currently controls all branches of government.
Saleh said he ordered the government to "fulfill the demands of the youth camping in Sanaa, Aden and Taiz and in other cities, but without sit-ins or chaos."
Shortly after Saleh finished his speech, some 4,000 people, mostly students, took to the streets and headed toward the main square in Sanaa, calling for his ouster. Saleh has ruled Yemen for 32 years.
Also in the capital, some 5,000 doctors, nurses, pharmacists and medics from all over the country marched toward the Sanaa central square. Wearing their white robes, they denounced this week's shooting of anti-government protesters by troops at Sanaa University. There were many women among the marchers Thursday.
"What a shame! What a shame! Peaceful demonstrations fired on," they shouted.
Opposition leader Yassin Said Numan said Saleh's reform plan has come too late.
"The president's initiative has been overtaken by events and facts on the ground today," Numan told The Associated Press. "If it had come six months ago, the matter would be totally different."
Nevertheless, he said the opposition parties would study the proposal before sending an official reply back to Saleh.
Saleh told the gathering that he was aware the opposition would reject his offer, but he had to let the people know about it.
Saleh pledged in his Thursday address that Yemen would hold general elections and form a new government by early 2012.
The government and the opposition agreed in 2009 to extend the current parliament's term for two years, until last month.
The Saleh-dominated assembly had wanted to hold parliamentary elections next month, but the opposition has rejected holding a vote without reforming the election law first. The dispute over the issue has stopped preparations for the election.
Sheik Hamid al-Ahmar, a leading member of the opposition and a member of Saleh's Hashid tribe, urged the president to spare the country more bloodshed by agreeing to step down before the end of this year. In a TV interview, he said the presidents of Tunisia and Egypt "served their countries" by stepping aside and said Saleh should do the same.
Al-Ahmar, a businessman who is believed to be interested in succeeding Saleh, denied he was seeking the presidency but said there was no going back now. "The youth uprising which has started will not stop," he said.
The tensions in Yemen escalated dramatically this week with the shooting Tuesday evening at the Sanaa University, when government troops fired live ammunition, killing one person and wounding scores of others.
Saleh's pledge not to run for re-election in 2013 has failed to defuse the protests, as have his calls for a unity government with opposition figures.
Even before Yemen was hit by the weeks of, the country was growing increasingly chaotic with a resurgent al-Qaida, a separatist movement in the south and a sporadic Shiite rebellion in the north vexing the government, which has little control outside major urban areas.