British Prime Minister Gordon Brown says he believesthe death toll fromthe violent crackdown on massive anti-government protests in Burma is"far greater" than military regime is reporting.

At least 10 peoplewere reported dead following12 days ofprotests that have consumed the country's two largest cities.

Hundreds of Buddhist monks and theirsupportershave been arrested, carted away in trucks at night or pummeled with batons in recent days, according to witnesses.

"I am afraid that we believe the loss of life in Burma is far greater than is being reported so far," Brown said Friday after a telephone meeting with U.S. President George W. Bush and Chinese Premier Wen Jiabao.

Brown called on the international community to step up sanctions and other pressure on Burma's military leaders to halt the violence.

Meanwhile Friday, the Burmese government cut public internet access as troops locked up Buddhist monasteries in an effort to crush ongoing demonstrations against the ruling junta,raisingfears that the crackdown on dissenting civiliansisabout to intensify.

Government soldiers wielding clubs beat demonstrators in a group of about 2,000 near the Sule Pagoda in Rangoon. At another one of Friday's sporadic protests in the former capital city, soldiers fired warning shots in the air to disperse a group of 200.

"The military was out in force before they even gathered and moved quickly as small groups appeared, breaking them up with gunfire, tear gas and clubs," Shari Villarosa, the top U.S. diplomat in Burma, also known as Myanmar,told the Associated Press byphone.

"It's tragic. These were peaceful demonstrators, very well-behaved," she said.

Authoritieshave also establishedno-go zones around five key Buddhist monasteries, one diplomat said, a move reminiscent ofprotests in 1988 that left thousands dead and others imprisoned.

Bob Davis, Australia's ambassador to Burma, said there were unconfirmed reports that "several multiples of the 10 acknowledged by the authorities" may have been killed by troops in Rangoon.

The government's decision tosuspend the services of two internet service providers Friday also raised concerns that the military was preparing to intensify efforts to quash the protests, which were sparked by the government's decision in August to double the price of fuel.

The tactic is reportedly an attempt to stem the flow of images posted to the web by Burmese bloggers, who have been e-mailing pictures and videos of the violent crackdown to foreign media services that are barred from the country.

"It will have a huge impact on us," said Aye Chan Naing, speaking in Oslo, Norway. His organization, the Democratic Voice of Burma, is responsible for many of the images being shown around the world.

"We believe it may kind of delay some time the way we can get the information out, but we still think we can get the information out from inside the country," he said.

Video believed to capture fatalshooting of Japanese journalist

The CBC's John Northcott, reporting from Tokyo, saidJapanese officials have received autopsy results for photographerKenji Nagai, 50, who was killed during Thursday's protests. The results suggest the Japanese journalist died of a direct gunshot woundto the chest, contradicting earlier reports that Nagai was killed by a bullet that had ricocheted.

An image posted on the website of Japanese TV network Fuji showed Nagai lying in the street, camera still in hand, with a soldier pointing his rifle down at him. The site alsofeatures a videoof security forces opening fire on protesters, including a man falling forward after apparently being shot at point-blank range.

Burma's opposition shortwave radio station, based in Norway, identified the victim as Nagai.

The government's use of violence against peacefuldemonstrators has attracted international attention, sparking protests across the globe.

The U.N.'s special envoy to Burma, Ibrahim Gambari, is en route to the country and could arrive by Saturday to meet with generals to discuss a political solution to the crisis.

Speaking under condition of anonymity, a Western diplomat said Burma's decision to let Gambari in "means they may see a role for him and the United Nations in mediating dialogue with the opposition and its leaders."

In Geneva, diplomats said the U.N. Human Rights Councilwill call anemergency session on Tuesday after Western countriesled a petition that won the support of one-third of the body's 47 nations.

The U.S.said it willfreeze any assets held by 14 top officials in the junta within U.S. jurisdiction, and ban U.S. citizens from doing business with them.

China, Burma's economic and political ally,and Japan, its largest aid donor,bothrefuse to impose immediate sanctions.

With files from the Associated Press