Jakarta – A mob vandalized the offices of Indonesia's most prominent human rights group on the eve of unprecedented trials for atrocities in East Timor that were allegedly committed by Indonesia's army and allied paramilitary gangs. Three generals are among those to face the courts for crimes against humanity.

On Wednesday, dozens of people with sticks and stones broke into the Jakarta headquarters of the Kontras group. They smashed windows and broke computers, said activists who claimed the attack was a scare tactic.

One activist was beaten up in the attack. The group, a fierce critic of Indonesia's military, has long called for key officers to be tried for brutality both in East Timor and in Indonesia.

Wednesday's attackers ripped up documents related to several cases the group is probing. They complained that Kontras had failed to investigate the deaths of four pro-military civilian guards during political turmoil in Indonesia in 1998.

However, Kontras member Doni Ardianto rejected this as an excuse and said the attack was designed to intimate activists involved in high-profile trials of senior Indonesian officials accused of East Timor rights abuses. The trials are scheduled to start Thursday. "We suspect that they are trying to intimidate us because ... of the rights tribunal," he said. "We are not scared. We are used to it."

Kontras has been the target of several attacks since it was formed in 1999.