East Timor's army chief, Taur Matan Ruak, accused the international security forces in his country yesterday of failing to prevent the attacks, and called for an international investigation to determine the full facts.

East Timor's President, Jose Ramos Horta, remains in an extremely serious condition in Royal Darwin Hospital after being shot in circumstances which are prompting speculation.

East Timorese Prime Minister Xanana Gusmao survived an assassination attempt, while rebel leader Alfredo Reinado was killed during the gunfight at Dr Ramos Horta's home.

Mr Gusmao's Australian-born wife, Kirsty Sword Gusmao, told last night how their home was surrounded by armed men just minutes before her husband was attacked by armed rebels.

She told ABC TV that during the time between when Dr Ramos Horta was shot and her husband's convoy was ambushed, armed men surrounded their home.

"There was a great sort of panic and confusion," she said. "I got the children dressed as quickly as I could and had them lie under the bed, all the while unsure of actually how many we were talking about.

"We only had a very small security contingent actually with us at the time." She tried to call her husband to tell him the family was in trouble, but his convoy was being attacked.

Reports last night suggested East Timor's prosecutor general was close to issuing arrest warrants over the assassination attempt.

Doctors said Nobel laureate Dr Ramos Horta would have to remain in an induced coma at least until tomorrow as they repaired a gunshot wound to the lung.

A company of heavily armed Australian troops poured into the tiny nation's capital, Dili, yesterday, as Prime Minister Kevin Rudd warned more violence could erupt.

"My knowledge of East Timor over the years is that we really have to watch how events unfold, it can be quite volatile," Mr Rudd said yesterday.

The Australian forces expected to play a role in rounding up supporters of Reinado.

Confusion surrounds the attempted assassination, with reports suggesting Dr Ramos Horta's security guards fired before the rebels did, and questions being raised about the rebels' easy movement around the city.

Brigadier Baker said the attacks shocked everyone.

"It came as a surprise to us all," Brigadier Baker said.

"Unless we had information that led to the time and the place it would occur, there wasn't a great deal that could have been done about it."

As a state of emergency was declared in Dili, finger-pointing began, with East Timor's Commander Ruak blaming international forces, which include the Australian-led International Stabilisation Force, for failing to prevent the assassination attempts.

"Given the high number of international forces present in East Timor, in particular within the capital, how is it possible that vehicles transporting armed people have entered the city and executed an approach to the residences of the President ... and the Prime Minster without having been detected?" he said.

"There has been a lack of capacity shown by the international forces, who have primary responsibility for the security within East Timor to foresee, react and prevent these events."

Mr Rudd said Australia had not established exactly what happened during the firefights.

"There is still a lot of uncertainty about what actually transpired," he said.

He would not comment on the adequacy of the President's security, but said he had previously stayed at Dr Ramos Horta's house where the shooting took place.

A curfew was imposed over Dili, outlawing public gatherings after dusk, and a heavy security presence was in place across the city, with UN police and international troops patrolling the streets and local police manning checkpoints on key roads. Defence said Australia was sending almost 200 soldiers and about 70 extra police.

HMAS Perth arrived in Dili harbour yesterday to support the military effort on the ground.

In Darwin, Australian Foreign Minister Stephen Smith discussed the crisis with his East Timorese counterpart, Zacharias da Costa.

He repeated that the Australian Government called off a manhunt for Reinado last year at the request of the East Timorese Government.

"The East Timorese Government and the President in particular thought that they could affect a negotiator-agreed solution or compromise," he said. "I don't want to reflect on whether that was a good thing or a bad thing, but obviously in light of events that will be one of the things the East Timorese Government will reflect on."

Reinado was among 600 mutinous soldiers dismissed by East Timor's Government in 2006, triggering violence in which 37 people were killed and more than 150,000 people forced from their homes.

with agencies