Richard Galpin, Jakarta – In Indonesia, a nation of almost 200 million Muslims, the radical fringe is getting increasingly angry with the US and its allies. Anti-US demonstrations have been getting steadily bigger as the US prepares for possible military action over the 11 September attacks on Washington and New York.

In the latest one about 2,000 people gathered in the centre of Jakarta, right next to the British embassy. One of the most radical groups, the Islamic Youth Movement, has warned it will call a jihad or holy war if Afghanistan is attacked, unless it has seen clear evidence of Osama Bin Laden's involvement in terrorism. It claims more than 500 people have already signed up.

"If one Afghan is hurt or killed we'll boycott American goods," said the group's self-styled commander, Handrian Syah. "If two, we'll search for Americans living in Indonesia. If three, we'll take the life of the American ambassador here. If more, we'll destroy the American embassy."

Direct challenge

President Megawati Sukarnoputri has appealed for calm and condemned the threats of violence. Over the past three years, since the downfall of the authoritarian ruler Suharto, several extremist organisations have come to the fore – in particular Laskar Jihad, whose leaders say they have connections with Afghanistan. It dared to set up a training camp close to the capital to prepare thousands of men to fight against the Christian community in the Moluccan islands. In recent days it has had another recruitment drive as the crisis between the US and Afghanistan has escalated.

Whilst not wanting to go into specifics, one of its leaders, Ayip Syaffudin, made it clear they were preparing for action. "We'll see how big the American military operations against Afghanistan are – the bigger their action, the bigger our reaction," he said. "We can tell from President Bush's speech that the Americans' real policy is to launch a crusade – that means by attacking Afghanistan they'll be digging their own grave."

Moderate views

The vast majority of Indonesia's Muslims are renowned for an extremely moderate approach to their religion. Most reject the threats made by the extremists and are concerned about the impact this will have on the country's image as a bastion of liberal Islam. This is also a concern for President Megawati, who recently visited Washington, where she pledged support for America's war on terrorism. But few want the government to give unconditional support to the United States.

The views of one man, Rio, about last month's suicide attacks in New York and Washington are widely held. "It's tragic what happened in America, thousands of people killed," he said. "But in my opinion we can say that America is an arrogant country – maybe it's a punishment from God so they won't be so arrogant anymore."

The country's largest and most moderate Muslim organisation is Nahdlatul Ulama. It has more than 30 million members. Uleel Absor Abdullah, a senior official, said anger at the United States was widespread. "Deep in their mind, in their heart, there is understanding that America did already a lot of bad things towards Muslim countries," he said. "The Palestinian question is among the most important things here. So they already know that America is playing bad or good role everywhere in the world and this tragedy is kind of a result of that role that America plays."

And he is worried American military action in Afghanistan will simply play into the hands of the Islamic extremists. "I'm feeling bad if America retaliates against Afghanistan because this action will reinforce the conservative feeling among a certain group here," he said. "So it is like an escalating cycle, not only in Indonesia, but I think everywhere."

Given the current hostile atmosphere, some American expatriates have already begun leaving Indonesia. Large foreign companies such as Nike and Adidas have also pulled out some non-essential staff. They know the security forces cannot be relied on for protection. So far the police have done very little to reassure the foreign community that they will be able to control the extremists if Afghanistan does come under attack.