Australian troops began arriving in East Timor on Tuesday to help enforce a state of emergency declared after a double assassination attempt that left the tiny nation's president in hospital with triple gunshot wounds.

An Australian warship also arrived off the Dili coast on Tuesday to support the first of 200 fast reaction troops sent to reinforce international security forces as doctors said President Jose Ramos-Horta would remain on life support until next week.

In the Australian city of Darwin, where Ramos-Horta was airlifted with gunshot wounds in the chest, back and stomach, doctors were planning more surgery.

"His condition remains extremely serious, but by the same token, stable," Royal Darwin Hospital general manager Len Notaras told reporters, adding the President would need more surgery in the next 24-36 hours.

"He will be in an induced coma until at least Thursday, intensive care until Sunday or Monday of next week," he said.

In the capital Dili, East Timor's interim president Vicente Guterres declared a state of emergency and appealed for calm, after apparently coordinated attacks against the president and prime minister threw the young nation into a fresh crisis.

Around 1,600 U.N. police, backed by about 1,000 Australian soldiers, were patrolling Dili and other cities amid fears of fresh violence by rebel soldiers, whose leader Alfredo Reinado was killed in the surprise early morning assault.

"The government of East Timor is in firm control," said Australian Prime Minister Kevin Rudd, ahead of a visit to the troubled nation later this week.

INTERNATIONAL FORCES CRITICISED

The commander of East Timor's military, Brigadier General Taur Matan Ruak, called for an investigation into Monday's attacks and questioned the role of international forces.

"There has been a lack of capacity shown by the international forces who have primary responsibility for the security within Timor Leste (East Timor)," he told a news conference.

He also urged the public and media to persuade Reinado's followers, who had fled into the jungle, to return for dialogue.

Schools, businesses and government institutions were open in Dili, as local police stopped and checked cars, but the calm appeared uneasy and residents admitted they were nervous.

Meetings and protests are banned under the emergency, and all citizens must stay home between the hours of 8 p.m. and 6 a.m.

"I am going back home early because I'm afraid of gang fighting or protests," said Antonio Gomes, a high school student.

Ramos-Horta, 58, who shared the Nobel Peace Prize in 1996 for waging a nonviolent struggle for independence, was shot at his home early on Monday by renegade soldiers.

His bodyguard was injured and two rebel soldiers died in the shoot-out, which the East Timor government said was a coup attempt. One of the dead men was identified as Reinado.

Prime Minister Xanana Gusmao escaped a similar attack that left his car riddled with bullets.

U.S. President George W. Bush condemned the assassination attempts. "Those who are responsible must know that they cannot derail democracy in Timor-Leste," Bush said in a statement.

Australia's Foreign Minister Stephen Smith, who was meeting his East Timor counterpart Zacarias da Costa in Darwin on Tuesday, has said that up to 20 rebels were involved in the assassination attacks, divided into two groups of 10.

"Now we would hope that given that the rogue ring leader is now dead that there might be some peaceful and amicable way of his supporters returning to the fold or at least handing in their arms," said Smith.

Asia's youngest nation has been unable to achieve stability since hard-won independence. The army tore apart along regional lines in 2006, triggering factional violence that killed 37 people and drove 150,000 from their homes.

Foreign troops were needed to restore order.

Reinado had led a revolt against the government and was charged with murder during the 2006 factional violence.

But Ramos-Horta had met Reinado for talks as recently as January in a bid to reach a deal in which rebels would give arms in return for talks on outstanding grievances and legal issues.

Analysts said a split among Reinado's rebel soldiers may have led to the attack by backing the rebel leader into a corner.

"In recent weeks, significant divisions have emerged amongst the sacked 600 soldiers. Large groups of whom have been wanting to go it alone and get a negotiated settlement," Mark Aarons, co-author of "East Timor: A Western Made Tragedy", wrote in the Australian newspaper.

The former Portuguese colony of almost 1 million people gained full independence in 2002 after a U.N.-sponsored vote in 1999, marred by violence, ended more than two decades of brutal Indonesian occupation.

The predominantly Roman Catholic country, though one of Asia's poorest nations, straddles key shipping lanes, is strategically important for neighbours Australia and Indonesia, and has potentially lucrative oil and gas reserves.