SANAA, Yemen, (AP) – The U.S., European and Gulf Arab ambassadors were trapped inside a diplomatic mission Sunday by an armed mob angry over a deal for Yemeni President Ali Abdullah Saleh to step down after 32 years in power. Prospects that Saleh would sign the pact as promised were thrown into doubt.

Wielding knives, daggers and swords, hundreds of Saleh loyalists blocked the entrances to the United Arab Emirates Embassy, where at least five ambassadors were gathered in expectation the embattled leader would arrive to sign the deal.

“Everybody is worried. We can’t leave the embassy,” said a Saudi diplomat, who spoke on condition of anonymity because of the sensitivity of the subject.

Pro-Saleh militiamen dressed in traditional Yemeni dress roamed the streets of the capital, especially outside embassies, and blocked the road to the presidential palace.

At one point, armed men attacked a convoy of the Gulf Cooperation Council’s chief mediator, secretary-general Abdullatif bin Rashid al-Zayani, to try to keep it from reaching the UAE Embassy, witnesses said. Pounding the car, they shouted against Gulf intervention in Yemeni affairs.

The convoy of the Chinese ambassador also came under attack by armed men before a police detail was deployed to clear the way and disperse the crowd.

Saleh has backed away from signing the U.S.-backed deal at least twice before, adding to the opposition’s deep mistrust of a leader known for adept political maneuvering that has kept him in power for decades. The deal, mediated by the six-nation Gulf Cooperation Council, calls for Saleh to step down within 30 days and transfer power to his vice president. It also would give him immunity from prosecution.

Yemen’s opposition coalition signed the deal Saturday, based on what it said were guarantees the president would sign the next day. But a ruling party statement early Sunday said Saleh objected to signing “behind closed doors” and wanted a public event attended by the opposition.

An official in the Saudi capital, Riyadh, said the GCC would drop the proposal and withdraw from mediation if Saleh did not sign by the end of the day.

Even if Saleh goes ahead with signing, it was far from certain whether that would satisfy the many different groups protesting his rule in the streets.

Hundreds of thousands poured into a central square Sunday that has become the center of opposition protests, waving Yemeni flags and shouting rejection of the deal. They held banners that read: “Now, now Ali, down with the president!” and “Go out Ali!”

Women mingled with men, unlike in previous protests when female protesters stood on the edge of the square segregated from men, in keeping with Sharia law that mandates separation of the sexes. Children had their faces painted with Yemeni flags, while youths carried pictures of slain protesters. Young men and women held a 6-foot-long (2-meter) Yemeni flag.

The protesters say the deal falls short of their demands for Saleh’s immediate departure and the dismantling of his regime. They also reject any immunity for the Yemeni leader and say the opposition parties don’t speak for their demands.

“This initiative is only meant to save Ali not Yemen. We are going to continue our revolution until the end. Like Tunisia and Egypt, we will go against the opposition if they form a government while Saleh is still in power,” declared Tawakul Karman, a protest leader and senior member of the opposition Islamic fundamentalist Islah Party.

She said the protesters were escalating their push by calling a nationwide general strike.

On Saturday, Saleh condemned the proposed deal as “a coup” and warned the U.S. and Europe that his departure would open the door for al-Qaeda to seize control of the fragile nation on the edge of Arabia.

In what appeared to be a state-orchestrated move to show a security void, dozens of pro-Saleh loyalists gathered in front of the Police Academy, where the ruling party general assembly had convened to discuss the deal. “We are coming under pressure, to reject the initiative,” said Mohammed Saad, a general assembly member.

Dozens of other supporters erected a big tent in one of Sanaa’s main streets, blocking traffic and raising banners that read: “Don’t go, don’t sign!”

Saleh has managed to cling to power despite near daily protests by tens of thousands of Yemenis fed up with corruption and poverty. Like other anti-government movements sweeping the Arab world, they took inspiration from the popular uprisings in Tunisia and Egypt.

The president has swung between offering concessions, taking them back and executing a violent crackdown that has killed more than 150 people, according to the opposition, which says it compiled the tally from lists of the dead at hospitals around the nation.

The bloodshed triggered a wave of defections by ruling party members, lawmakers, Cabinet ministers and senior diplomats. Saleh’s own tribe has joined those demanding his ouster. Several top army commanders, including a longtime confidant who heads a powerful armored division, joined the opposition and deployed their tanks in the streets of Sanaa to protect the protesters.

Saleh has been able to survive thanks to the loyalty of Yemen’s most highly trained and best-equipped military units, which are led by close family members.

That has raised concerns the political crisis could turn into an armed clash between the rival military forces if a deal is further delayed.

Seeking to win some support in the West for his continued rule, Saleh has warned several times that without him, al-Qaeda would take control of the country.

The United States, which had supported Saleh with financial aid and military equipment to fight the country’s dangerous al-Qaeda branch, has backed away from the embattled leader.

Al-Qaeda in the Arabian Peninsula has an estimated 300 fighters in Yemen and has been behind several nearly successful attacks on U.S. targets, including one in which they got a would-be suicide bomber on board a Detroit-bound flight in December 2009. The explosive device, sewn into his underwear, failed to detonate properly.

The proposed deal — first put forward in March by Saudi Arabia, Qatar, Kuwait, Oman, Bahrain and the United Arab Emirates — gives a clear timetable for a transfer of power.

One week after Saleh signs, the opposition takes leadership of a national unity government that will include representatives of Saleh’s party. Parliament will then pass a law granting him legal immunity and a day later — 30 days after the deal is signed — he is to step down and transfer power to his deputy.

A month after that, presidential elections are to be held.