Fri Sep 28, 11:42 AM ET

WASHINGTON - US President George W. Bush and British Prime Minister Gordon Brown led renewed calls on Friday for the Myanmar junta to end its violent crackdown on pro-democracy protesters.

Discussing the crisis in Myanmar by videoconference, Bush and Brown expressed "the need for countries around the world to continue to make their views clear to the junta, that they need to refrain from violence and move to a peaceful transition to democracy," White House spokesman Scott Stanzel said.

Security forces fired warning shots and used baton charges to clamp down on protests in Myanmar's two biggest cities on Friday, the third day of a crackdown that has left at least 13 people dead.

Amid mounting international anger, even the junta's southeast Asian neighbours expressed their "revulsion".

While the United States tightened economic sanctions, China, the closest ally of the generals running Myanmar, was also working to end the deadly unrest in Yangon.

China's Premier Wen Jiabao told Japan's new Prime Minister Yasuo Fukuda that Beijing was making efforts to calm the situation, Japanese officials said.

"The international community should play a constructive role and China will also make an effort," a Japanese foreign ministry statement quoted Wen as saying in a telephone conversation with Fukuda.

Wen also voiced hope that a visit to Myanmar by UN special envoy Ibrahim Gambari would produce results.

China and Japan have faced Western criticism for continuing to do business with Myanmar's military regime.

Meanwhile, the UN Human Rights Council called a special meeting on the Myanmar unrest in Geneva for Tuesday.

Portuguese ambassador Francisco Xavier Esteves, speaking on behalf of the European Union's presidency, said: "Urgent situations require urgent action and the Council must work to help find a solution."

Public outrage over the shooting of demonstrators in Yangon spilled over into clashes between Australian police and protesters outside the Myanmar embassy in Canberra.

There were also public demonstrations outside the Myanmar missions in London, Paris, Geneva, Rome and major Asian cities.

Hundreds of people who gathered outside the Myanmar embassy in Rome included ministers from the centre-left government.

"We must not be discouraged and throw in the sponge, we must do everything possible to defend the monks in Myanmar," said Emma Bonino, Italy's minister for European affairs and foreign trade.

Prime Minister Romano Prodi urged China and another Myanmar ally, India, to use their "authoritative influence" to call off the troops.

French socialist presidential candidate Segolene Royal joined demonstrators in Paris.

About 2,000 Myanmar people gathered outside their country's embassy in Malaysia. There were smaller protests at the Myanmar missions in Manila, Jakarta and Phnom Penh.

The 10-nation Association of Southeast Asian Nations (ASEAN), which has traditionally held back from criticising one of its members, took a stronger line.

ASEAN ministers meeting at the UN headquarters in New York "were appalled to receive reports of automatic weapons being used and demanded that the Myanmar government immediately desist from the use of violence against demonstrators," Singapore Foreign Minister George Yeo said.

The ministers "expressed their revulsion to Myanmar Foreign Minister Nyan Win over reports that the demonstrations in Myanmar are being suppressed by violent force and that there has been a number of fatalities," he said.

In Manila, Philippine President Gloria Arroyo called for the release of democracy leader Aung San Suu Kyi and other political prisoners.

ASEAN member Vietnam also urged Myanmar to cooperate with the UN envoy.

Earlier the US administration ordered a freeze on the assets of Myanmar's military leader Than Shwe and 13 other senior officials.

The US State Department has been adding Myanmar officials, regime supporters, and family members to a list of people barred from entering the United States, a White House spokesman said.

US Secretary of State Condoleezza Rice said: "I can just assure you that the US is determined to keep an international focus on the travesty in Rangoon (Yangon)."