JAKARTA -- An Indonesian military court on Saturday sentenced three soldiers to prison for rape during operations against separatist rebels in Aceh Province, a radio station reported.

Chief private Seprianus received the heaviest sentence of three years and six months. First private Husni Dwila was sentenced to three years and first private Awaluddin was jailed for two years and six months, Elshinta radio reported.

The maximum sentence is 12 years in prison.

All three soldiers were ordered discharged from the military.

"The accused, first private Awaluddin ... is proven legally and convincingly of carrying out the criminal act of rape," Major Trias Komara said as he sentenced the first accused.

His statement was broadcast on Elshinta from the Aceh city of Lhokseumawe where the trials occurred.

"The accused is sentenced to two years and six months in prison," said the judge, explaining that Awaluddin's action had damaged the army's image and traumatized the victims. Prosecutors had demanded three years in prison for Awaluddin, three years six months for Dwila and four years for Seprianus.

All three soldiers, members of the army's chief combat force Kostrad, were charged with raping four women between June 20 and 22 in North Aceh, a military spokesman said earlier.

Prosecutors told the court that one of the privates had forced a woman to perform a sex act in front of his fellow soldiers and female villagers.

The military has a record of gross rights abuses during earlier campaigns in Aceh but said it will try to ensure its troops behave better during the current campaign.

In an earlier trial, a military court jailed six soldiers for between four and five months for beating up civilians during the operation, which began on May 19 to wipe out separatists from the Free Aceh Movement (GAM).

In a report early this month, Indonesia's national human rights commission, Komnas HAM, said the operation appears to be failing to win the hearts of the Acehnese people.

Colonel Ditya Sumarsono said Saturday the military has killed 485 rebels and seized 223 weapons, with the loss of 45 soldiers and policemen, during the first two months of the operation. He said 1,029 rebels had been arrested or surrendered. At the start of the operation the military estimated the rebels' strength at about 5,000.

GAM says most of the people killed have been civilians.

Six government health workers escaped injury Saturday when their blood transfusion vehicle, which was marked as belonging to the Indonesian Red Cross, was fired on just outside the Aceh capital Banda Aceh, Red Cross chairman, Sanusi Maha, told AFP.

A bullet shattered the front window of the minibus which had just collected blood from the local air force base, Maha said. He did not know who the attackers were.

The military reported Saturday that troops shot dead five rebels, including a woman, during an exchange of fire in East Aceh on Friday.

The New York-based Committee to Protect Journalists (CPJ) Thursday said restrictions on foreigners in Aceh have made it almost impossible to learn "anything of substance" about the military campaign.

GAM has been fighting for independence since 1976. An estimated 10,000 people, mostly civilians, have been killed since then in the province on Sumatra island.