AFP, MANAMA: Bahrain's Sunni Muslim ruling family came under increased pressure to open in-depth negotiations with the Shiite-led opposition, as protesters erected more tents on the capital's Pearl Square.
Dozens of workers also joined the protesters, and more than 1,000 medics marched on the square to demand the resignation of the health minister, whom they accused of slowing aid to protesters during a deadly police crackdown.
After nightfall, an AFP correspondent reported thousands more people converging on the roundabout, which has been the focal point of demonstrations that have rocked the small but strategic Gulf kingdom since February 14.
The opposition has also called a large protest for Tuesday afternoon in the hope that tens of thousands of people will converge on Pearl Square, according to the INAA, Bahrain's main Shiite opposition group.
An early morning raid on Thursday resulted in the deaths of four people and was followed by the army deploying in the square.
But protesters flocked back on Saturday after the army was ordered back to base.
Riot police fired tear gas in an unsuccessful attempt to disperse them but then withdrew as Crown Prince Salman, deputy commander of the armed forces, ordered both police and troops to hold back.
After their first night since returning to the square passed peacefully, protesters erected more tents on Sunday afternoon, signalling they were not planning to leave any time soon.
With the focus switching to talks rather than clashes, Bahrain's main trade union called off a general strike it had organised for Monday, saying its main demand for the right to demonstrate peacefully had been met.
"In the light of the army's withdrawal and respect of the right to demonstrate peacefully, the general union for labour syndicates has decided to suspend the general strike and return to work on Monday," the union said.
The tiny, oil-rich ally, which has Sunni rulers governing over a restive Shiite majority near Shiite but non-Arab Iran, also houses the headquarters of the US Fifth Fleet.
US Secretary of State Hillary Clinton urged restraint in Bahrain on Sunday, blasting as unacceptable any violence by the Gulf kingdom's security forces and calling for immediate political reform.
During a call to Saudi Foreign Minister Prince Saud al-Faisal about the wave of protests gripping the Middle East and North Africa, Clinton "underscored the necessity of restraint by the security forces in Bahrain," the State Department said in statement.
And US ambassador to the United Nations Susan Rice said the wave of unrest sweeping the Arab world was a clear signal that societies were ripe for reform.
"What we're seeing across the region is a yearning for change, a hunger for political reform, economic reform, greater representation, and we support that," Rice told NBC's "Meet the Press."
The heir to Bahrain's throne has been tasked by his father, King Hamad, with launching a wide-reaching dialogue with the opposition.
But emboldened by Arab uprisings which have toppled the strongmen of Tunisia and Egypt since last month, the opposition has raised the stakes, demanding a "real constitutional monarchy" and the government's resignation.
Prime Sheikh Khalifa bin Salman, an uncle of the king, has held office since independence from Britain in 1971 and is widely despised by the opposition.
"The government that was unable to protect its people must quit and those responsible for the massacres must be judged," said Abdel Jalil Khalil Ibrahim, head of the INAA parliamentary bloc.
"The opposition does not refuse dialogue but they ask for a platform that is favourable to dialogue."
Another INAA MP, Ali al-Aswad, told AFP that opposition groups had held talks to "prepare a document summarising their positions," including forming a committee to draw up a new constitution to be put to a referendum.
Regional heavyweight Saudi Arabia, meanwhile, voiced its "absolute rejection" of foreign meddling in Bahraini affairs, pledging to stand by its neighbour.
And Riyadh and Abu Dhabi, partnered with Manama in the six-nation Gulf Cooperation Council, urged the opposition to heed government calls for talks.
Prince Salman himself acknowledged the need for reform but called for calm first. "There are clear messages from the Bahraini people... about the need for reforms," he said in a television interview.
EU foreign affairs chief Catherine Ashton said it was vital that the promised dialogue "should begin without delay."
In a telephone call to the crown prince, British Foreign Secretary William Hague said he expressed "the UK's deep concern about the situation and strong disapproval of the use of live ammunition against protesters."
The unrest has also cast doubt on next month's season-opening Bahrain Grand Prix, with Formula One chief Bernie Ecclestone saying it may be moved to a later date.
