Ali Abdullah Saleh, Yemen's president, has offered to step down from his post by the end of the year as protests against his rule continue in defiance of a deadly crackdown by security forces.
Saleh pledged a "constitutional" transfer of power, and added that he would not hand over power to the military. Addressing military leaders, he warned against "coups" said the country faced a civil war if he was forced from office. Several senior officers have backed protesters in recent days.
The offer comes with Saleh under renewed scrutiny following the declaration on Friday of a nationwide state of emergency after a violent crackdown on anti-government protests killed at least 41 people, and left scores more wounded, in the capital Sanaa.
But a coalition of Yemeni opposition groups rejected Saleh's offer. "The opposition rejects the offer as the coming hours will be decisive," said Mohammed al-Sabry, a spokesman for the main umbrella opposition group.
A similar proposal by Saleh was the subject of discussions between him and opposition groups earlier this month. Saleh has already promised not to run for another term when his current term expires in 2013.
But he has a history of breaking similar promises: In 2005, he vowed not to run for another term in office, only to run and win another term in 2006.
Speaking to a group of army officers on Tuesday, Saleh warned against "coups," clearly a message to senior military officers who have defected over the past 24 hours.
"Those who want to climb up to power through coups should know that this is out of the question. The homeland will not be stable, there will be a civil war, a bloody war. They should carefully consider this," he said.
Major-General Ali Mohsen Al-Ahmar, the head of the north-western military zone and the first armoured division, announced his support for the protesters following a brutal crackdown.
Other high-ranking officers that have defected include Brigadiers Hameed Al Koshebi, head of brigade 310 in the Omran area; Mohammed Ali Mohsen, who heads the eastern division; and Nasser Eljahori, head of brigade 121.
General Ali Abdullaha Aliewa, an adviser to the Yemeni supreme leader of the army, also deserted the president.
Saleh warned on Tuesday that any further defections would have consequences.
The developments led to tanks being deployed on Monday in the streets of Sanaa, the capital, creating a potentially explosive situation and prompting the defence minister to declare that the army still backed the president.
The current crisis has also prompted the Arab League to condemn "crimes against civilians" in Yemen and urge the government to deal with the people's demands in a "peaceful manner".
The Arab League "strongly condemns the crimes committed against civilians, and calls for concerted efforts to safeguard national unity and the right to free expression," representatives meeting in Cairo, said in a statement.
They also called for "dialogue and democratic methods to deal with the demands of the Yemeni people in a peaceful manner"
'Demand for change'
Yemen's ambassador to France says President Saleh must step down to avoid further bloodshed
Saleh's support in diplomatic circles also appeared to be vanishing,with Robert Gates, the US defence secretary, expressing concern on Tuesday.
Yemen is considered a key ally by Washington which has backed Saleh's campaign against al-Qaeda militants in the country.
"We are obviously concerned about the instability in Yemen," Gates said on Tuesday, warning that instability could lead to a "diversion of attention" from the fight against al-Qaeda.
Meanwhile Abdel-Wahhab Tawaf, Yemen's ambassador to Syria, said he was stepping down and joining colleagues who have quit in protest.
Speaking from the Syrian capital, Damascus, Tawaf said he was resigning over dozens of Yemenis fatally shot by snipers on Friday near Sanaa University, for weeks the centre of demonstrations.
Yemen's ambassadors to Saudi Arabia, Lebanon, Egypt, the Arab League and China have also resigned or expressed support for the protest movement.
Huda al-Baan, Yemen's human rights minister, also resigned from the government and the ruling party in protest over Friday''s attack.
Abdullah Alsaidi, Yemen's ambassador to the UN, told Al Jazeera: "I think there is now a demand for change and we are all for a peaceful change. I appeal to the president and to all the others to work for a peaceful transfer of power."
Speaking in Paris, Alain Juppe, the French foreign minister, said resignation for Saleh was "unavoidable" and pledged "support to all those that fight for democracy".
Meanwhile, the country's most powerful tribal confederation Hashed, which includes Saleh's tribe, issued a statement asking the president to respond to the people's demands and leave peacefully.
But the US and Saudi Arabia - Saleh's closest allies - have appeared nervous about his stepping aside after being in power since 1978 and there currently being no clear successor.