Thousands of soldiers and police locked down Myanmar’s largest cities Sunday, keeping even the most die-hard protesters off the streets. Scores of overnight arrests further weakened an uprising to end decades of military dictatorship.

The soldiers were deployed while U.N. envoy Ibrahim Gambari was in Myanmar, trying to persuade its rulers to end a deadly crackdown on demonstrators that has sparked international outcry.

China and Japan also have urged their political and economic ally to resolve the crisis peacefully, but such international pressure has had little impact in the past.

The number of troops in Yangon, the largest city, swelled to about 20,000 after reinforcements arrived overnight Sunday, ensuring that almost all demonstrators would remain off the streets, an Asian diplomat said.

“The security forces are demonstrating their strength,” said the diplomat, who spoke on condition of anonymity, citing protocol. “I think the chance of protesters coming to the road and mobilizing enough people to topple the junta is zero.”

The demonstrations began last month after the government sharply increased the price of fuel, but the focus soon shifted to frustration with decades of brutal military rule. Crowd sizes mushroomed to at least 70,000 in the past week after monks, highly revered in this Buddhist nation, started spearheading the marches.

The junta, which has a long history of snuffing out dissent, cracked down Wednesday and Thursday, opening fire into a crowd of peaceful protesters and chasing others down with batons. Though the official death toll is 10, foreign diplomats say the number is likely much higher.

Most monks are now barricaded inside monasteries, which have been locked from outside with soldiers bearing automatic rifles standing guard.

On Sunday, a few monks were seen, going around a neighborhood on their customary morning round for alms.

“We are not going to protest any more. Rather we will conduct peaceful protests. We Buddhist believe that dhamma (Buddha’s teachings) will finally win over evil,” said one monk.

People suspected of leading or organizing this week’s rallies continue to be arrested, the Asian diplomat said, estimating the total number could be as high as 1,000. They joined an estimated 1,100 other political detainees who have languished in jails since before the current turmoil began.

With the main prison now overcrowded, people are now being detained in university buildings and educational institutes, he said.

A resident who identified himself as Ko Hla wrote on his Internet blog that troops in downtown Yangon were searching every bag.

“If someone got caught with a camera in it, they would arrest him. They arrested anyone that they suspect,” Ko Hla wrote.

The crackdown has triggered an unprecedented verbal flaying of Myanmar’s generals from almost every corner of the world even some criticism from No. 1 ally China, which said it was “very much concerned about the current situation.”

It urged the ruling junta to “exercise restraint and use peaceful means to restore its stability as soon as possible.”

Gambari was taken on arrival Saturday to Naypyitaw, the remote, bunker-like capital where the country’s military leaders are based. His schedule was not made public.

Groups of people gathered outside shops in Yangon listening to foreign radio broadcasts for an update on Gambari’s visit.

“We apologize to foreigners for feeling unsafe … People in this country are very nice and gentle, but the soldiers are very rough,” said one resident. Monks and residents spoke on condition of anonymity fearing reprisals.

The White House urged the junta to allow Gambari to also have access to pro-democracy leader Aung San Suu Kyi the Nobel Peace Prize laureate who is under house arrest.

“We are not very hopeful, but it’s the best shot we have,” Singapore’s Foreign Minister George Yeo said at the United Nations in New York.

Many people see China, Myanmar’s biggest trading partner, as the most likely outside catalyst for change.

But China, India and Russia do not seem prepared to go beyond words in dealing with the junta, ruling out sanctions as they jostle for a chance to get at Myanmar’s bountiful and largely untapped natural resources, especially its oil and gas.

The Association of Southeast Asian Nations, or ASEAN, a 10-member bloc which includes Myanmar, also gave no indication that it is considering an expulsion or any other action.

Activists from Myanmar and foreign countries also called for urgent action.

“The world cannot fail the people of Burma again,” said the National Coalition Government of the Union of Burma, an exile group based in Washington. “Selfless sacrifices deserve more than words and lip-service. They want effective intervention before it is too late.”