Eight Chinese nationals have spent a second night on the roof of a Sydney detention centre as authorities struggle to negotiate a breakthrough.

深圳夜生活

Five men and four women climbed on to the roof of a wing of the Villawood Immigration Detention Centre at 8am (AEST) on Wednesday.

They threatened to throw themselves off on Thursday afternoon, according to Jamal Daoud, of the Justice Action Network, if their demands were not met.

Dr Daoud is in regular telephone contact with the rooftop protesters, who are demanding to be given protection visas.

One of the protesters was brought down in a cherrypicker at 4pm (AEST) on Thursday.

He was understood to be negotiating on behalf of the group of Chinese nationals, one of whom is believed to be aged 32 and two months pregnant.

They all claim to have been on a hunger strike since Monday.

Bottles of water were passed up to the roof while inflatable mattresses were placed at the foot of the building late in the day.

But no deal appeared to have been reached by dusk, raising the prospect of the remaining protesters having to spend a second night on the roof.

Ramesh Fernandez, CEO of refugee advocate group RISE, said they were severely dehydrated and that he was extremely worried about their state of mind.

“They are serious – you don’t joke around when people say they are going to commit suicide,” he said.

“I just spoke to them and they are in a really weak condition at the moment….

“They are really frustrated and angry at the way they are getting treated, especially by the guards and the Department of Immigration who are not going to engage with them in compromise.”

The group is believed to have come from China’s Fujian province. They have been in Australia for between two and six months, entering the country on student and tourist visas.

Their demonstration comes after the end of a 30-hour protest by 11 other asylum seekers on the roof of another wing of the detention centre.

A spokesman for the Department of Immigration and Citizenship reaffirmed that the protesters’ activities would not change the way the department dealt with their claims.

“Their activities will not alter the department’s processing of their cases,” he said.

Meanwhile, Opposition Leader Tony Abbott said the system was under “extraordinary strain”.

“I accept that not all of the people who are protesting at Villawood arrived illegally by boat, but certainly, the boat arrivals since the government adopted new policies has put, it seems, almost unbearable strain on the system,” he told reporters in Sydney.

Asked if it was odd that police hadn’t been called to help move them off the roof, Mr Abbott replied: “This is a operational matter and I really don’t want to go into that.

“I’m not on the spot and it would be wrong for us to suggest how these delicate and tense and dangerous situations should be resolved in any specific way.

“But the point I make, the whole system is under almost unbearable stress, because this is a government that has failed to stop the boats.”