Jakarta – United States President Barack Obama must challenge Indonesia over its abuse and torture of Papuan civilians during his talks in Jakarta this week, human rights activists said on Monday.

The call came after an Indonesian military tribunal hearing a case of torture was described as a "farce" and a "grand deception" designed to deflect criticism ahead of Obama's arrival on Tuesday.

Top military officers had said the trial Friday in the Papuan city of Jayapura – which is off-limits to foreign journalists – would deal with five soldiers allegedly involved in the gruesome torture of two Papuan men in May.

President Susilo Bambang Yudhoyono had also promised "no immunity" for military torturers after a video of the incident – in which one victim's genitals are burned with a fiery stick – was posted online ahead of a visit to Jakarta last week by Australian Prime Minister Julia Gillard.

But despite such assurances and repeated statements from military officers, it emerged late Friday from Jayapura that the trial was about a different, less serious case of abuse which occurred in March.

The Sydney Morning Herald, which first reported the existence of the online video of the May incident, said in a report Monday that the Jayapura tribunal had "proven to be a grand deception" and US-based Human Rights Watch said it was just another example of Indonesia's refusal to bring soldiers to justice for gross human rights abuses in the far eastern province. "This should be at the top of the agenda when President Obama visits Jakarta," said Phil Robertson, HRW deputy director for Asia.

Obama's 24-hour visit to the mainly Muslim Southeast Asian country comes hot on the heels of the Pentagon's announcement in July that it would resume ties with Indonesia's special forces, accused of widespread abuses and killings.

US Defence Secretary Robert Gates announced in Jakarta in July that the United States would lift a 12-year suspension of contacts with the special forces as a result of "recent actions... to address human rights issues."

Few Indonesian military officers have faced justice for rights abuses dating back decades, including alleged crimes against humanity in East Timor and the killing of thousands of political activists during the Suharto dictatorship.

Papua and the Malukus have underground separatist movements which Indonesia regards as threats to its territorial unity. Activists are regularly given lengthy jail terms for crimes such as possessing outlawed rebel flags.