Australia is sending additional police officers and soldiers to East Timor following an assassination attempt on the country's president and prime minister. President Jose Ramos Horta has been flown to Darwin in northern Australia for treatment. Doctors say he is in serious condition after surgery. From Darwin, Phil Mercer reports.

Australia is sending 150 extra soldiers and police officers to its troubled neighbor to try to smother unrest after the shooting of the president.

The arrival of the Australian navy vessel HMAS Perth in the East Timorese capital, Dili, is a further indication of Australia's intent.

East Timor has declared a two-day state of emergency. Under the decree, police have additional powers, public gatherings are banned and a nighttime curfew is in place.

Australian foreign minister Stephen Smith held a news conference in Darwin with his East Timorese counterpart. Smith said he was 'deeply disturbed' by the attempted assassination and has called for the United Nations mandate in East Timor to be extended.

"I have indicated personally to the foreign minister on behalf of the Australian government the commitment that we announced yesterday, the contribution of additional troops and the contribution of additional police officers to ensure peace and stability and security in East Timor," said Smith. "The Australian government regards this as essential, just as we do the ongoing presence of the United Nations and a renewal of the United Nations mandate to see a continuing presence of the United Nations in East Timor."

East Timor's foreign minister, Zacarias de Costa, said the situation in Dili is calm, but he stressed that his country is in an extremely fragile position.

De Costa said he is confident that those responsible for the attack on President Ramos Horta will be caught.

The president has had two hours of surgery at the Royal Darwin Hospital to repair damage to a lung and to remove bullet fragments and shrapnel from his chest.

He is expected to undergo more operations this week. His doctors say he is very lucky to be alive and described his condition as serious. They are, though, optimistic that he will eventually make a good recovery.

The assassination attempt is a massive blow to East Timor. Six years after independence from Indonesia, it remains one of the world's poorest nations.

The East Timorese voted to secede from Indonesian control in a referendum in 1999 - a vote that will be remembered for the brutality of militiamen who tried to disrupt the process.

There was further unrest in 2006, which prompted the intervention of peacekeepers from Australia, New Zealand, Malaysia and Portugal.

Tens of thousands of people fled their homes during the fighting and many are still too afraid to return.

The road from independence has been a painful one for East Timor and analysts predict that foreign peacekeepers are likely to stay in the troubled country for years to come.