The government said some detainees in the Manus Island immigration processing centre in PNG were refusing food and some had engaged in self-harm, while others were staging a "peacefull protest".
Reports emerged yesterday of a hunger strike at the facility, which the government initially said was incorrect.
Today a spokesman for Immigration Minister Peter Dutton told SBS: "A small number of transferees have engaged in self harm. They have been offered appropriate medical care."
"There are also a number of transferees who are refusing food and fluids, again they are being offered appropriate support."
The spokesman added that both Australia and PNG remain committed to the regional resettlement arrangements.
One man required emergency medical treatment after he swallowed razor blades, Refugee Action Coalition spokesman Ian Rintoul said.
Video footage apparently shot at the Manus Island detention centre shows detainees protesting and chanting for their freedom.
SBS obtained footage shot inside the centre, along with a series of images, from an asylum seeker named Ali* who said there was a mass hunger strike underway.
The grainy footage was said to be shot on Wednesday evening and shows a group of men chanting "What do we want? Freedom!"
Some of the photographs show detainees sitting on the floor in a large room.
Ali told SBS via telephone that the men had gathered there in protest and were refusing to return to their rooms.

"More than 220 people didn’t go for breakfast and lunch today and others will join us tomorrow."
Another image showed an asylum seeker who appeared to have his lips sewn shut.
Mr Rintoul said as many as 500 detainees have stopped eating and drinking and that at least 15 others have sewn their lips together.
The detainees are protesting against their lengthy detention, poor conditions, and the prospect of resettling in Papua New Guinea.
“They see both the immigration department and the PNG government as effectively throwing them to the wolves. Even for people who have been found to be refugees, there is no safe resettlement on Papua New Guinea “ Mr Rintoul said.
A water-supply problem at the centre has reportedly led to water being cut off until further notice, with asylum seekers unable to access showers.

Ali told SBS the asylum seekers wanted to be handed over to the United Nations.
"Australia doesn't want us, that is OK," he said. "We just ask that they give us to the United Nations.
"We didn't come to PNG, we didn't enter PNG soil and we haven't done anything in this country so we shouldn't be in jail in this country."
Fifty people deemed to be genuine refugees are due to be moved into the community on the 22nd of January.
But Greens Senator Sarah Hanson-Young said that would only put them at risk.
"They don't feel safe about living in the community on Manus Island because we've got to remember that 12 months ago they were beaten, bashed and one man died at the hands of locals."
Locals are angered at the prospect of refugees being resettled in an already overburdened community.
Mr Rintoul said the detainees were extremely vulnerable.
"They have no facilities, they haven't got education arrangements, they haven't got accommodation, they haven't got medical clinics and it is quite understandable why looking at what the Australian government has dumped on them, that there is a level of resentment."
A government spokesperson yesterday said "media reporting that transferees are refusing food and fluid is incorrect."
*Name has been changed
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