SYDNEY: A fresh rooftop protest broke out at an Australian immigration detention centre Wednesday, officials said, just hours after the end of another tense standoff that followed the suicide of an inmate.

Nine people, reported by activists to be mainly Chinese nationals, climbed onto the roof of the Villawood centre in Sydney, the immigration department said, just 12 hours after a separate group of Tamil men were coaxed down.

"The department can confirm that nine detainees began a rooftop protest at about 8:00 am today," a spokesman told AFP. "These detainees are not illegal maritime arrivals," he stressed.

The spokesman could not confirm their nationality or whether they were seeking asylum, nor comment on activists` statements that the group included four women, one of whom is pregnant.

Television footage of the protest showed at least one woman on the roof.

Centre staff were negotiating with the group to try and bring them down safely, the spokesman added.

Eight Sri Lankan Tamils ended a 30-hour rooftop standoff with authorities at the centre Tuesday night after negotiations with the United Nations refugee agency (UNHCR). They had threatened to jump if their cases were not reviewed.

Their protest followed the death of Fijian Josefa Rauluni, 36, who leaped from a roof in front of horrified onlookers on Monday, shortly before he was due to be deported.

Australia has a policy of mandatory detention for asylum-seekers while their claims are processed, and generally holds detainees on remote Christmas Island in the Indian Ocean.

But increasing numbers of illegal immigrants arriving by boat -- more than 4,000 so far this year -- have forced the reopening of mainland centres, including Villawood, which houses about 300 people.

BDST: 08:58 HRS, September 22, 2010