Lindsay Murdoch, Jakarta – Indonesian immigration officials yesterday freed 29 foreigners, including 18 Australians, who were detained at an international conference in Jakarta, as criticisms grew of police-sanctioned brutality against the organisers.

The conference secretary, Ms Romawaty Sinaga, said the police tactics in using a gang of thugs parading Islamic symbols to attack the Indonesian organisers had reignited fears of police and military repression during the 32- year-old rule of the dictator Soeharto. The thugs wielding swords and sickles, who had accompanied police to the conference, attacked the Indonesian organisers after the foreigners, including a four-year-old Australian girl, had been taken away by police for questioning over suspected immigration offences.

But after two days of high tension which involved almost 24 hours of detention by most of the foreigners, an Immigration Department spokesman, Mr Marsanudin Gani, said an examination of the passports of 29 of 30 foreigners had revealed they had committed no offences. Only a Pakistani participant had entered the country on a tourist visa and faced trial or deportation, he said.

Mr Gani said the rest of the foreigners had obtained free short visit visas on arrival in the country that allowed them to attend meetings or conferences.

Sydney women Ms Pip Hinman and her daughter Zoe had been allowed to return to Australia on Saturday night after being among those detained the day before. Police who had acted aggressively towards the foreigners yesterday offered no apology for the blunder.

One of Australians, Dr Helen Jarvis, of the School of Information at the University of NSW, said being allowed to go free was a "tremendous relief". Threats to deport the foreigners were "something fabricated, it would seem". Dr Jarvis was reluctant to speculate on the motive for the raid. "I suppose people are trying to clamp down on democratic space," she said. "None of us thought we had committed any violations. We went through an extremely awful experience and it turned out all right."

But Dr Jarvis said the conference organisers who were attacked were not as lucky. One man suffered a severed artery when one of the attackers thrust a broken glass into his neck. Seven others were hurt. Dr Jarvis said the police were "extremely aggressive" when the group arrived at police headquarters yesterday morning before being taken to immigration offices. She said that acting on the advice of lawyers, the group refused to be fingerprinted. But police tried again, unsuccessfully, to fingerprint them at the immigration offices.

The chairman of Indonesia's Institute for Human Rights Research, Mr Abdul Garuda Nusantara, said Friday's raid was a direct violation of the freedom of assembly. Police "have clearly breached one of the important principles of the Universal Human Rights Declaration," Mr Abdul said. "This will only worsen Indonesia's image before the international community as the conference was attended by activists from foreign countries."

The Jakarta Post said in a scathing editorial that not only did the thugs who attacked the organisers seem to have the tacit support of the police, "but they finished off the police's job in dissolving the gathering".