Police on the Indonesian island of Lombok have been told to shoot rioters on sight to try to end the religious violence.

Gangs of Muslim youths are reported to be roaming the streets, burning and looting premises and homes owned by Christians. They have also tried to block a ferry terminal in Lombok's capital Mataram.

Hundreds of troops and police are trying to contain the situation.

National Police Chief Lieutenant General Rusdiharjo told local civic and religious leaders that police would take "harsh security measures" against rioters, SCTV private television said.

The clashes in Lombok have prompted fears that religious violence may engulf the Indonesian archipelago.

Tension is reported to have spread to the neighbouring island of Sulawesi, where Muslim rioters have barricaded several streets and attacked the properties of non-Muslims.

President Abdurrahman Wahid on Wednesday denied his government was in crisis, saying the violence could be brought under control.

Cabinet Secretary Marsilam Simanjuntak said Mr Wahid had ordered security personnel to take "stern action".

Violence spreads

The rioting in Lombok started after a rally to protest against continuing violence between Muslims and Christians in the Moluccas in which more than 500 people have died this year.

Since Monday, almost a dozen churches have been attacked on Lombok as well as many offices, shops and private homes. Three people are reported to have died in the violence.

Hotels and business on the island have put up signs reading "God is Great" in an attempt to ward off attacks.

Some hotels have hung Muslim prayer mats outside their premises hoping the gangs will pass on.

About 3,000 non-Muslims, mainly Christians and Hindus, are reported to have sought refuge in army and police. Thousands of others are reported to have fled the island all together.

Tourists flee

Tourists have also been leaving. A spokesman for the Holiday Inn at Lombok's Senggigi beach said it had started evacuating all guests by ferry to neighbouring Bali.

Fifty Australians were airlifted out by their government. Extra flights have been laid on and diplomats say that the remainder of Lombok's expatriates are expected to leave on Wednesday.

The Australian foreign affairs spokesman, Paul Robillard, said he had received a report on the situation on Lombok from the Australian consul on Bali.

"He tells me the situation overnight there was very tense - mobs on the street and a lot of violence. As far as we are aware, the vast majority of Australian tourists and residents have left in the last 24 hours," Mr Robillard said.

Indonesian officials involved

President Wahid has suggested that officials may have been involved in the violence.

"There are indications of the possibility of the involvement of officials, whether deliberate of not deliberate," he was quoted as saying by his cabinet secretary.

The co-ordinating minister for political and security affairs, General Wiranto, played down the possibilities of violence spreading further. He said simply that "that it would not spread to other regions."

But a BBC correspondent in the Indonesian capital Jakarta, Richard Galpin, says that the government's failure to take prompt action to deal with the problem in the Moluccan islands is clearly now having repercussions around the country.

Lombok is 40 kilometres (25 miles) east of Bali, Indonesia's main tourist destination. The unrest is likely to further damage the country's once-lucrative tourism industry.