Palu, Central Sulawesi – Human rights groups in Palu, Central Sulawesi, urged the police Friday to investigate attacks on student activists allegedly by hired thugs.

Activists from the Anti-Corruption Students Coalition (KMAK) staged a peaceful rally at the Palu District Court on Thursday, demanding Tadulako University rector Sahabuddin Mustapa be convicted for corruption.

Sahabuddin is currently on trial on charges of misappropriating Rp 7.2 billion (US$800,000) in educational funds. After the rally, a mob of around 100 people believed to be hired thugs attacked the students.

"A student suffered a stab wound to his hand in the incident... from a sharp weapon," Huisman Brant, director of the Central Sulawesi chapter of the Legal and Human Rights Advocacy Development Studies Center (LPS HAM), told The Jakarta Post on Friday.

LPS HAM leaders condemned the attack, which took place in the presence of police personnel. A second attack occurred at GOR Park, situated across the street from Palu city police headquarters.

Leaders of LPS HAM, the Commission for Missing Persons and Victims of Violence and the Indonesian Lawyers Institution in Palu demanded police investigate the attacks and arrest the perpetrators. "We are disappointed in the police for not escorting the KMAK student activists during the peaceful rally," Huisman said.

Rector Sahabuddin had earlier been put under city arrest, but the order lapsed on May 28. Prosecutors handed his case files to the Palu District Court on May 31.

During the trial Thursday, presiding judge Faturahman reinstated the defendant's city arrest, but allowed him to carry out his duties as rector of the only state university in Palu until his legal status was determined.