(CNN) -- East Timor declared a 48-hour state of emergency Tuesday one day after assassination attempts on President Jose Ramos-Horta and Prime Minister Xanana Gusmao.
"Demonstrations and gatherings are suspended," in addition to an overnight curfew being imposed from 8 p.m. until 6 a.m., Deputy Prime Minister Jose Luis Gutteres told CNN.
Australian security forces, expected to include several hundred troops and up to 70 police, were expected to arrive Tuesday afternoon at East Timor's request, according to the Australian Department of Defense Web site.
Ramos-Horta meanwhile remained in an induced coma in a military hospital in Darwin, Australia, and could face additional surgery after being shot twice in the back, Gutteres said.
One of the bullets tore through Ramos-Horta's abdomen, and he was on full life support after being transferred from East Timor.
"The president is in ICU and is in stable condition," Gutteres said Tuesday. "He may have surgery today or tomorrow to repair his lungs."
One of Ramos-Horta's bodyguards and two attackers were also killed, including rebel leader Maj. Alfredo Reinado.
Gusmao also faced gunfire separately but escaped unharmed.
Bullet fragments removed from Ramos-Horta have been given to Australian Federal Police for forensic examination, the Australian Associated Press reported.
The next few days were critical for the president, in terms of keeping infection at bay, Royal Darwin Hospital official Len Notaras told ABC Radio, adding that Ramos-Horta was "extremely lucky to be alive."
"His condition remains extremely serious, but by the same token, stable," Notaras told ABC Radio, according to the Australian Associated Press.
Ramos-Horta shared the Nobel Peace Prize with Carlos Filipe Ximenes Belo in 1996 for their work toward a peaceful solution to the conflict in their country.
Under the rule of the late Suharto, Indonesia occupied East Timor for a quarter century, during which more than 100,000 people were killed, according to human rights groups.
East Timor gained independence in 2002.
In March 2006 a strike by about 600 East Timorese soldiers against alleged discrimination in the military led to their dismissal. The soldiers set up armed camps in the countryside, prompting the dispatch of additional peacekeepers from Australia, Malaysia, Portugal and New Zealand.
Reinado, the Australian-trained former head of East Timor's military police joined the revolt and became its leader. He was later captured but broke out of prison and returned to lead disaffected troops, said Damien Kingsbury, an analyst at Australia's Deakin University.
Two small parties in Gusmao's government had supported the rebels, and the government had been trying to coax Reinado to give up peacefully, Kingsbury said.
But a secondary plan had been developed to move against him by force if necessary, Kingsbury added, saying, "It's quite possible that he got wind of this plan and decided to act accordingly." E-mail to a friend