A prayer rally in the province of East Java in Indonesia, the world's largest Muslim-populated country, attracted hundreds of thousands of Muslims to pray for peace and a non-violent end to the Iraq crisis.

An open field across from the provincial military command in provincial capital Surabaya teemed with people gathered for the two-hour "national" mass prayer organised by the country's largest Muslim movement, the Nahdlatul Ulama (NU).

Crowd estimates varied, with witnesses putting the numbers at between 100,000 and 500,000 and a policeman on guard who identified himself as Agus said there were more than 500,000 people in attendance at the prayer meeting in the NU stronghold, which opened and closed without incident.

NU Chairman Hasyim Muzadi briefly addressed the gathering and called on Washington to refrain from attacking Iraq. "This is for international interests. It would be better to leave this to the United Nations to handle," Muzadi said.

The aim of Sunday's rally, he added, was to seek counsel from God to help ensure the safety of the nation and "prosperity" for the world. A new "National Repentance Movement" launched by the NU would be "the start of introspection for the leaders and the nation of Indonesia," Muzadi said.

Popular young cleric Abdullah Gymnastiar, meanwhile, attracted a congregation of thousands to the Istiqlal main mosque in the capital Jakarta for a sermon in which he preached non-violence and the need for honest government.

Gymanstiar had told journalists this week that following Sunday afternoon prayers he, escorted by a legion of supporters, would hand-deliver an open letter to US President George W. Bush asking that he refrain from attacking Iraq to the US embassy about a kilometer down the road from the mosque.

Gymnastiar did not elaborate on the contents of the two-page letter to Bush and acknowledged he did not expect a reply.

"Let Mr. Bush ask his deepest conscience whether he really represents the people of the United States," he said.

"I really fear the negative impact of war. As a human, I am worried at the dangerous attitude of Mr. Bush, who so far has refused to listen to the people of the world." Some 700 policemen joined another 700 military personnel, NU youth guards and members of the organising committee in overseeing the Surabaya event, which also included prayers for peace in the Middle East and in the restive Indonesian province of Aceh. There were no disruptions reported.

Present at the rally were Foreign Minister Hasan Wirayuda, Religious Affairs Minister Said Agil Husin al-Munawar, Defence Minister Matori Abdul Jalil, Army Chief General Ryamizard Ryacudu and former president Abdurrahman Wahid.

Also present were the ambassadors of friendly countries, including Iraq, Iran and Kuwait, as well as a representative from Palestine. Among the some 300 clerics onstage were 50 clerics from the staunchly Muslim province of Aceh at the tip of Sumatra island.

"Hopefully, the prayers of humankind can be heard by Washington. Hopefully the ears and the eyes of the US leaders can be opened by this prayer," Wirayuda said late Saturday.

Close to 90 percent of the Indonesian archipelago's 214 million people practice Islam.

Indonesia has said it supports the presence of UN weapons inspectors in Iraq but opposes any unilateral action against Baghdad.