The Syrian government called for an urgent Arab summit to discuss the deepening crisis and invited Arab League officials to visit before its membership suspension was to take effect on Wednesday.
In a significant concession, the government said the Arab officials could bring any civilian or military observers they deem appropriate to oversee implementation of an Arab League plan for ending the violence.
The 22-member bloc's vote on Saturday was a stinging rebuke to a regime that prides itself as a bastion of Arab nationalism and left it increasingly isolated over its crackdown on an eight-month uprising that the U.N. estimates has killed more than 3,500 people since mid-March.
Sunday's protests in support of the government drew large numbers in the capital and four other cities - a turnout helped by the closure of businesses and schools.
"You Arab leaders are the tails of Obama," read one banner held by protesters accusing the Arab League of bowing to pressure from the U.S. president.
Thousands of people carried red, black and white Syrian flags and posters of President Bashar Assad in a Damascus square. Similar demonstrations were held in the cities of Aleppo, Latakia, Tartous and Hasakeh.
The Syrian leader asserts that extremists pushing a foreign agenda to destabilize Syria are behind the country's unrest, rather than true reform seekers aiming to open the country's autocratic political system. Sunday's demonstrators accused Arab countries of being complicit with the purported conspiracy.
The government called the Arab League decision "illegal," claiming it was intended to set the stage for foreign military intervention like in Libya.
However, the offer to allow a visit by an Arab League ministerial committee and accompanying monitors appeared to signal some will to try to implement an Arab League-brokered deal for ending the violence that the government has so far seemed unwilling, or unable, to do. The Nov. 2 deal calls for Syria to halt attacks on protesters, pull tanks out of cities and hold talks with the opposition.
Members of the Syrian opposition rejoiced and saw they vote as a step toward greater recognition.
"This gives strong legitimacy to our cause. ... We consider this decision to be a victory for the Syrian revolution," Bassma Kodmani, a spokeswoman for the Syrian National Council opposition group, told The Associated Press.
The pro-government protests came after a night of assaults by demonstrators on the diplomatic offices of countries critical of the Syrian regime, including break-ins at the Saudi and Qatari embassies and attacks at Turkish diplomatic posts across the country.
The embassy attacks are likely to stoke anger in Arab states against the regime in Damascus. Arab disapproval in itself may not seriously damage President Assad's hold on power, but if Syria further antagonizes Gulf states, it risks having them build up the Syrian opposition into a unified body that can win international recognition, as happened during Libya's civil war this year.
Syrian security forces had confronted Saturday night's protesters at embassies with batons and tear gas but were unable to stop a group from breaking into the Qatari embassy and bringing down the Qatari flag and replacing it with the Syrian flag. Others entered Saudi Arabia's embassy compound, broke windows and ransacked some areas, the kingdom's media reported.
The kingdom strongly condemned the attack in a Foreign Ministry statement and said it held the Syrian authorities responsible for protecting its interests.
Saudi King Abdullah, who has condemned Assad's crackdown, had already recalled the Saudi ambassador to Syria in August. Kuwait and Bahrain have also recalled their ambassadors.
Protesters also tried to break into the Turkish Embassy in Damascus Saturday and into the country's consulates in the cities of Aleppo and Latakia, Turkey's state-run Anatolia news agency reported. Turkey is not a member of the Arab League but has also been sharply critical of Syria's crackdown, and Turkey's foreign minister welcomed the League vote.
Turkey on Sunday sent a plane to Damascus to evacuate the families of its diplomats as well as nonessential staff, Anatolia reported. Turkish Foreign Ministry officials were not immediately available for comment.
On Sunday, hundreds of baton-carrying Syrian riot police in helmets ringed the U.S., Qatari, Saudi and Turkish embassies - all located in the capital's upscale Abu Rummaneh district. Three fire trucks were parked in front of the Turkish Embassy. The Turkish and Qatari embassies were closed for the day but the Saudi Embassy was operating, an operator said.
Associated Press writers Suzan Fraser in Ankara, Turkey, and Albert Aji in Damascus, Syria, contributed to this report.