Jill Jolliffe, Dili – The United Nations may be facing new embarrassment in East Timor following reports that people arrested in last Wednesday's riots had been beaten in custody.

An informed source, who asked not to be named, said UN headquarters in New York had been told of the situation. "A UN inquiry has been requested, headed by an independent person from outside the Timor mission," the source said. "What happened was a total failure to provide security in East Timor, which is what the UN came here to do."

Ten prisoners are still being held and 67 others have been released. "We have taken cognisance of reports that some detainees may have been mishandled," a UN spokesman said. "We are committed to the highest standards of human rights and these reports will be investigated in that spirit."

What began as a student protest ended in a day of unchecked burning and looting. Protesting over the arrest of a classmate, the students had thrown stones at the police and attempted to storm their headquarters. The rampage began after police allegedly opened fire on demonstrators. Observers said they had first fired warning shots.

One student, Honorio Ximenes, 14, died at the scene, while Manuel da Silva, 18, died in hospital the next day. Sixteen other students were wounded and two of them remain in a critical condition.

Most of the arrests were made on Wednesday afternoon, in the wake of the the worst violence. Among the buildings burnt was the residence of Prime Minister Mari Alkatiri.

By Thursday morning, 77 people were being held at a hastily constructed detention centre on the outskirts of Dili. It was here that a few human rights officials first had access to the prisoners, who were later transferred to central Dili.

The alleged assaults ranged from light slaps to heavy punching and detainees reportedly had guns put to their heads. "Injuries consistent with these reports were witnessed at the holding centre," a source said. "There were split lips, bruises, black eyes and a suspected fracture."

The 10 remaining prisoners are due to appear in court tomorrow, although they have already been held beyond the legal period of 72 hours, an infraction that also has been the subject of complaints by human rights groups.

Jose Luis Oliveira, of the Association for Law, Human Rights and Justice, East Timor's leading human rights organisation, said police had refused to allow one of his officials to visit the prisoners.

"We have had reports of violence against the prisoners," he said. "No matter what they've done, they have a right to be well treated. Our police are ignorant on human rights and are repeating what the Indonesians did."

He said the association sees the United Nations as having final responsibility. "It was they who trained them," he said.