Indonesian security forces have used torture and inhumane treatment to force confessions from suspected separatists and their sympathizers in the province of Aceh, where the government and rebels have fought a long-running conflict, a human rights group alleges in a report to be released Monday.

The incidents included cigarette burnings, electric shocks and beatings with rifle butts and hammers, Human Rights Watch says in its 56-page report. The group based its allegations on interviews with 33 adults and two juveniles who were convicted of rebellion and sent to five prisons in Java, Indonesia's main island.

"I was processed like an animal," one 30-year-old Acehnese prisoner told Human Rights Watch. "They hit me with a wood beam and a gun butt, and they poured water over me, and every day I was hit. . . . After fainting, they would pour water over me again and hit me again."

The organization accuses the Indonesian military and police of violating Indonesian law and international standards of fairness and due process in handling prisoners. In most cases, it says, arrests were made without warrants and defense attorneys did not participate in trials. No witnesses or evidence other than the accused prisoners' confessions were produced in court, the report says.

"The scale of torture and the failure of due process documented in this report makes it clear that these are systemic failures, not just the acts of rogue soldiers and police or untrained, poorly resourced judges and prosecutors," the report states, noting that some detainees displayed scars they said were left by the abuse.

"In the Indonesian security forces, there's a real culture of impunity right now," said Sam Zarifi, deputy director of the Asia division of Human Rights Watch.

A Foreign Ministry spokesman, Marty Natalegawa, dismissed the allegations as unfounded. "We would not be that stupid and careless and irresponsible to commit the sort of abuses mentioned," he said. "If anything, we have been at pains to ensure at every step of the way the proper legal framework within which authorities can conduct themselves."

The current conflict in Aceh between the separatists and the Indonesian military began in 1976. In May 2003, after peace talks faltered, President Megawati Sukarnoputri declared martial law and the military resumed operations. A security force of at least 40,000 has been fighting a guerrilla force that initially numbered about 5,000.

The military says it has killed more than 2,000 rebel fighters and captured thousands of others. The rebels say most of the casualties have been civilians. Although martial law was lifted after a year, the province remains under a state of civil emergency.

Several detainees interviewed by Human Rights Watch admitted they were members or sympathizers of the Gerakan Aceh Merdeka, or Free Aceh Movement, known as GAM. But a majority said they had no ties to the rebel group, the report says.

Twenty-four of the 35 interviewed said they were tortured so that they would confess to involvement with GAM. Sometimes, the torture lasted for days, they said. The 11 others were severely mistreated, ostensibly to punish them for presumed ties to the rebels, the report says.

In many cases, prisoners said they made false confessions so the beatings would end.

"If it was the morning, I was beaten by two men," said a 16-year-old detainee. "If it was the evening, I was beaten by the guard on duty. . . . I was beaten for three days and three nights . . . and we were shocked with electric current."

Human Rights Watch called on Indonesia's incoming president, Susilo Bambang Yudhoyono, to condemn the torture, investigate the allegations and discipline offenders.

Yudhoyono, a retired four-star general who tried to broker peace talks with the Acehnese rebels, said last week that he hoped the conflict would be settled fairly and peacefully.