An Indonesian appeals court has sentenced four Australian members of a drug smuggling ring to death, prompting a protest from the Australian government, officials said Wednesday.

But the court spared the lives of two other Australians, sentencing them to life in prison.

The fate of the men — part of a trafficking ring dubbed the "Bali Nine" by the media — has been followed closely in Australia, which does not have a death penalty. If carried out, the death sentences could strain ties between the two countries.

CountryWatch: Indonesia

"We are grateful that the Indonesians are being tough on drugs. It's just that we don't support capital punishment," said Australian Foreign Minister Alexander Downer. "We will, at the appropriate time, support appeals for clemency."

The four men now facing death — Scott Rush, Tan Duc Than Nguyen, Si Yi Chen and Matthew Norman — originally received life terms for trying to take home more than 18 pounds of heroin from Indonesia's resort island of Bali last year.

The cases have wound through the judicial system since the original convictions, with defense attorneys and prosecutors both appealing. The first round of appeals saw Rush's life sentence upheld, while Nguyen, Chen and Norman's punishments were cut to 20 years.

Rush appealed his verdict to the Supreme Court, while prosecutors asked judges to reinstate the original sentences of the others.

However, the Supreme Court ruled last month that all four would face the firing squad, said Mulyadi, a court official who attended the hearings. No reason was given for the decision.

Zarof Ricard, another Supreme Court official, said two other convicted drug smugglers — Michael Czugaj and Martin Stephens — had been sentenced to life imprisonment.

Lawyers for the men said they had yet to be informed of the verdict.

The men, aged 19 to 23, were arrested with five other Australians in April 2005, some at Bali's airport with heroin taped to their bodies and others in a hotel room purportedly plotting another shipment.

The two ringleaders — Andrew Chan, 22, and Myuran Sukumaran, 25 — are already facing death.

The final member of the "Bali Nine," Renae Lawrence, decided against challenging her 20-year sentence, which was reduced from life on appeal.

Australia's drug laws are more liberal than those in most Asian nations, and its government routinely asks that death sentences imposed on its citizens by foreign courts be commuted to time in prison. It is unlikely to take any steps in this case until the legal process is complete.

The Supreme Court's director of crime, Zarof Richard, said the four men had the right to file a final appeal known as a judicial review. If that fails, they could seek a presidential pardon, but that would require an admission of guilt.

Indonesia often sentences drug smugglers — both foreign and local — to death. There are about 65 people awaiting execution in Indonesia, many of them Africans or Asians convicted of drug trafficking.

The country last executed drug smugglers in 2004 — an Indian man and two Thai women.

The government is under pressure to crack down on rampant illegal drug use that kills scores of young, mostly poor people each year.