JAKARTA — A military court in Jakarta opened the trial Wednesday of four Indonesian service members accused of carrying out an acid attack on human rights activist Andrie Yunus. The defendants are charged with serious premeditated assault in the March attack and face up to 12 years in prison if convicted.

The defendants were identified as Sgt. Edi Sudarko, First Lt. Budhi Hariyanto Widhi Cahyono, Capt. Nandala Dwi Prasetya and Air Force First Lt. Sami Lakka. Three are navy marines and one is an air force officer, all assigned to military intelligence.

On the evening of March 12, Yunus, 27, was riding his motorcycle in central Jakarta when assailants hurled a vial of hydrochloric acid at his face. He suffered chemical burns to about 20% of his body and damage to roughly 40% of his right cornea. He has undergone several surgeries and remains in recovery, which prevented him from attending the trial's opening, according to military prosecutor Mohammad Iswandi.

"The actions of the defendants who threw chemical liquid on Andrie Yunus, resulting in the loss of sight in his right eye and severe burns with no hope of complete recovery, were inappropriate actions for members of the TNI." military prosecutor Iswandi told the court. He said one of the accused obtained rust removal fluid from a military workshop and mixed it with battery fluid before the group searched for Yunus on motorbikes.

After the indictment was read, the defendants, two of whom sustained minor facial and eye injuries from acid splashes during the attack, did not file objections. Through a military-appointed defense lawyer, they indicated they would not dispute the indictment. The four men are alleged to have acted together, with the motive described as personal.

Human rights groups criticized the framing of the motive as personal and the decision to try the case in a military court instead of a civilian one. "This case has been narrowed to just four individuals, without transparency, while the motive is framed as personal." said Usman Hamid, executive director of Amnesty International Indonesia. "It is difficult to accept that state facilities were used solely for personal revenge." he added. The Indonesian human rights watchdog Komnas HAM has claimed that at least 14 people were linked to the attack.

Yunus is deputy coordinator with the Commission for the Disappeared and Victims of Violence (KontraS). At the time of the attack, he had just finished recording a podcast criticizing the militarisation of the Indonesian government under President Prabowo Subianto. He had also participated in protests last year opposing revisions to Indonesia's military law that would expand the armed forces' role in civilian affairs.

Jakarta police initially handled the investigation before announcing that members of the Indonesian military were implicated. Six days later, military police arrested the four suspects from the Strategic Intelligence Agency of the Indonesian National Armed Forces (TNI). The agency's chief resigned after the arrests without providing a reason. Prabowo pledged to pursue those responsible and said he was considering an independent fact-finding team. The trial will resume on May 6, when the court will hear witnesses.