A Buddhist group claiming to be aiding monks drive an escalating protest movement in Myanmar called Saturday for nationwide prayer vigils in a bid to turn up the heat on the military regime.

The monks’ peaceful protests, which have drawn thousands of people onto the streets clapping and smiling in Yangon and other cities, have turned into the most prolonged show of defiance in nearly 20 years against the junta.

Deeply respected in the devoutly Buddhist country, the monks have breathed new life into the anti-junta movement after initial street protests broke out one month ago following a massive hike in fuel prices.

“We ask every citizen to join our vigils,” said a purported spokesman from The Alliance of All Burmese Buddhist Monks, an underground Buddhist group.

He was speaking by telephone from Myanmar and declined to give his name.

The vigils will start from Sunday for three days, and the group urged the public to stand outside their houses for 15-minute prayers from eight o’clock each night, the spokesman said.

“We want peace in Burma,” he said, using Myanmar’s former name.

Few details are known about the underground group, but analysts say it is mainly made up of young monks.

The mounting turmoil has raised concern in the international community, and British Foreign Secretary David Miliband has pledged to raise the issue at the UN General Assembly in New York next week.

Burma, which was under British conial rule until independence in 1948, has been run by the military since 1962.

The US and British ambassadors to the United Nations have also urged the junta to allow a visit by UN special envoy Ibrahim Gambari immediately.

On Friday, at least 3,000 people, led by Buddhist monks, marched along flooded streets in Yangon. Defying driving rain, the monks chanted Buddhist prayers calling for peace and security in the impoverished nation.

The junta normally does not tolerate even the slightest show of public dissent, and authorities have arrested over 150 people, including prominent pro-democracy activists, over the past month.

The arrested activists include Min Ko Naing, who is considered Myanmar’s most prominent opposition leader after detained democracy icon and Nobel peace laureate Aung San Suu Kyi.

Aung San Suu Kyi, 62, has spent most of the past 17 years under house arrest in Yangon.

Police so far have made no effort to stop the monks in Yangon over the past week, as the junta is worried that a violent crackdown on monks could trigger public outrage, analysts have said.

But the junta said in a rare admission Wednesday that it used tear gas and fired warning shots in the air to disperse 1,000 monks Tuesday in the oil town of Sittwe, 560 kilometers (350 miles) west of Yangon.

Monks have also demanded a government apology after soldiers beat protesting monks with bamboo sticks in early September in Pakokku, near central Mandalay, prompting young monks to briefly kidnap officials at a monastery.

Some monks have refused to accept donations from members of the military, a gesture seen as a severe rebuke tantamount to excommunication for Buddhists, who believe that giving alms daily is an important religious duty.

Monks are important cultural standard-bearers in Myanmar and were credited with helping rally popular support for a 1988 pro-democracy uprising which was crushed by the junta with the deaths of hundreds if not thousands of people.