Wed Sep 26, 10:53 PM ET

YANGON - Myanmar's generals launched pre-dawn raids on activist monasteries on Thursday, ignoring increasingly desperate international calls for restraint in their crackdown on the biggest anti-junta protests in 20 years.

Facing the most serious challenge to its authority since troops gunned down an estimated 3,000 protesters in 1988, the junta admitted one man was killed and three wounded when soldiers fired warning shots and tear gas at crowds on Wednesday.

Protest leaders, most of them from the revered Buddhist monkhood, said at least five monks were killed as soldiers and riot police tried to disperse the biggest crowds in a month of marches against grinding poverty and 45 years of military rule.

More bloodshed seemed inevitable as monks on Burmese-language foreign radio stations urged the clergy not to yield.

"We would like to call on the student monks to keep on struggling peacefully," one said on the Burmese-language service of the BBC. "Five monks have sacrificed their lives for our religion."

Some witnesses said as many as 100,000 people packed downtown Yangon, the former Burma's main city, on Wednesday and the streets echoed with a deafening roar of anger at the use of violence against the maroon-robed monks.

But the raids suggested the generals, who have lived with Western sanctions for years and frustrate their co-members of a Southeast Asian grouping with their refusals to heed calls for change, were not listening to the diplomatic clamor.

They dispatched military trucks to two monasteries in Yangon and arrested up to 200 of the monks accused of coordinating the demonstrations, witnesses said. Other sources said they also raided monasteries in the northeast.

Monks have been central to the protests that grew out of sporadic marches against a huge rise in fuel prices last month, as the Buddhist priesthood, the country's highest moral authority, goes head-to-head with the might of the military.

After a second night of dusk-to-dawn curfew, the streets of Yangon were unusually quiet early on Thursday, with a fraction of the normal traffic, witnesses said.

Soldiers had been moved from the downtown Sule Pagoda, the end-point of many of the marches, although armed police sat inside the locked shrine. Wooden barricades topped with barbed wire remained outside City Hall next door.

Police also arrested two senior members of the opposition National League for Democracy (NLD) from their homes, the party's spokesman said.

U.S.-RUSSIA CLASHES

The raids, arrests and likelihood of further violence against demonstrators who had marched peacefully until troops and police were poured into central Yangon suggested the generals would not deviate from the course they had plotted.

The international outrage was loud by any standards.

U.S. Secretary of State Condoleezza Rice called it a "tragedy" and urged the generals to allow a U.N. envoy to visit and meet detained pro-democracy leader Aung San Suu Kyi.

"The regime has reacted brutally to people who were simply protesting peacefully," Rice said on the sidelines of the U.N. General Assembly in New York.

U.N. Secretary-General Ban Ki-moon said he would dispatch special envoy Ibrahim Gambari to Southeast Asia to await permission from the generals to enter Myanmar.

History also suggests the generals will not be moved by threats from France and Britain, former imperial powers, that individuals would be held responsible for bloodshed. British Prime Minister Gordon Brown said the "age of impunity" was over.

There was no evidence of a united international approach.

The United States and the 27-nation European Union called on the generals to end violence and start a dialogue with pro-democracy leaders, including Nobel laureate Suu Kyi, and ethnic minority groups.

Foreign ministers of the Group of Eight industrial nations agreed on a similar formula but without a call for sanctions, in deference to Russia.

Participants said Rice and Russian Foreign Minister Sergei Lavrov clashed over the sanctions issue.

China and Russia, which have friendlier relations with the Myanmar authorities, have so far blocked any U.N. moves.

The United States and France called on China to use its influence to convince the junta to stop the crackdown.

Diplomats say China has privately been speaking with the Myanmar generals to convey international concern, but Beijing has so far refrained from any public criticism.