Members of the youth legion of the National Mandate Party rallied outside the Riau provincial parliament at Pekanbaru on Sumatra island, the state Antara news agency said.

Speakers said the attacks have turned Iraq into a killing field for innocent civilians and called for US President George W. Bush to be tried as a war criminal.

Demonstrators also criticised the United Nations as one of the parties responsible for the invasion. Many recent protests have highlighted the UN's failure to halt the invasion.

Meanwhile, police on Monday questioned Suaib Didu, leader of the radical Islamic Youth Movement (GPI) whose members allegedly harassed foreigners during an anti-war rally on March 24, group spokesman Adang Hidayat said.

Police have arrested 10 GPI members for allegedly trying to force foreigners to sign a document condemning the US invasion of Iraq.

Police accuse Didu of threatening others with violence, but it is not clear if he will be detained further, Hidayat said. Police could not be reached for comment.

Hidayat said the arrested GPI members had only requested the foreigners to join a poll on whether they were for or against the war on Iraq.

"Maybe our boys were so enthusiastic that the foreigners got scared," Hidayat told AFP.

In Riau, a thousand residents gathered in the town of Bengkalis to pray for an end to the war.

On Sunday around 200,000 people assembled peacefully in Jakarta in the biggest anti-war rally since the fighting started.

Vice President Hamzah Haz was quoted as saying on Monday that it may be necessary to consider a new and more independent UN.

Haz called for an organisation that could accommodate the aspirations of the majority of states instead of just a few, according to Masyhuril Chamis, an Islamic leader who met him.

WAR.WIRE