Jakarta – A hardline Muslim youth group warned on Thursday anyone backing Washington's self-declared war on terrorism should leave Indonesia, or risk being forced out.

The Islamic Youth Movement (GPI), which claims hundreds of its followers have signed up for a possible war against the United States, said it would be dangerous for any US supporters to stay in the world's largest Muslim nation after a possible strike against Islamic Afghanistan.

"We will evacuate anyone who supports the US aggression against Afghanistan ... regardless of his nationality. This even applies for Indonesians," GPI chairman Suaib Didu told Reuters.

The United States faces a growing Muslim backlash over a threat to strike Afghanistan in the hunt for Saudi-born militant Osama bin Laden, chief suspect in attacks on New York and Washington that left almost 7,000 dead or missing.

As Didu spoke, about 1,000 protesters from another Muslim group rallied outside the heavily-guarded US embassy a few hundred metres (yards) from his office, burning the US and Israeli flags in the latest daily outburst of anti-US passions. The demonstrators waved a large banner reading: "Attacking Afghanistan = war against Islam".

Hundreds of hardline Muslims at the weekend raided hotels in search for Americans and have warned them to leave the country. Didu said his group was planning similar action against citizens of US allies, not to scare foreigners but as a preventive security measure.

"After the revenge strike, there will be high passions and these people will certainly be targets. So, before anything happens, we want to escort them to the airport for their own safety. They can return when things calm down," he said. Asked what would his group do if they can not persuade people to leave, Didu said: "We love peace. We will not use any coercion. But if they refuse, they have to bear the risks."

Citing safety concerns, the US State Department on Wednesday authorised the evacuation of all non-emergency US government personnel and their families from Indonesia and advised American against travelling to the vast southeast Asian archipelago.