Several hundred students from Trisakti University gathered outside the military tribunal carrying banners demanding punishment for the perpetrators of last month's shootings.

Inside the courtroom, two of the officers listened to the military prosecutor read out charges of failing to stop their men from beating and shooting at the students.

The remaining 16 suspects are expected to be brought before the tribunal over the next week.

The killing of the Trisakti students was one of the turning points, leading to the fall of former President Suharto.

Until then the anti-government demonstrations by students had won sympathy but little practical support from the rest of the country. By opening fire without warning on what had been a peaceful protest outside Trisakti on May the 12, the security forces provoked widespread public outrage.

Over the following two days, Jakarta was engulfed in massive riots which human rights groups say left more than 1,000 people dead.

There was strong pressure on the authorities to find the culprits behind the Trisakti killings, but many students believe the 18 officers being charged are merely scapegoats.

They argue that a mysterious unit of army snipers was responsible for the deaths and that the truth is being covered up.