NAURU – Australia’s asylum seeking detainees on Nauru are standing by their allegations that guards assaulted people, allegedly including children, during a disturbance on Wednesday night.

The immigration department has denied the claims, but confirmed two detainees were treated for injuries after the incident, and that seven staff members were injured “while attempting to restore order to the centre and protect other residents, transferees and staff from injury”.

It is understood fighting broke out after a group of boys received a letter rejecting their request to be transferred to Australia.

A group of teenagers had written to authorities wanting to know why some asylum seekers who had arrived on the same boat had been allowed into Australia, yet they had not.

One witness said the boys who had been staging a protest for several days grew angry and frustrated prompting guards to take action.

The immigration department initially declined to address the allegations of violence, confirming only that a disturbance had taken place, two people were injured, and Nauruan police attended.

Later on Thursday a second statement labeled the detainees’ allegations that guards assaulted women and children as “false”, and said seven staff members had been hurt.

Immigration Minister Peter Dutton dismissed the assault allegations, based on the lack of advice he had received which supported it.

He said there was “a lot of misinformation being peddled”, and videos purportedly from inside the centre were “a complete outrage.”

“Because there is no evidence that people are being assaulted there, that’s not the advice that I’ve received,” he said.

Dutton was asked by ABC radio presenter Mark Colvin to “definitively” clarify his response to reports there were children involved in the disturbance. “I’m not advised there were children involved,” he said.

Guardian Australia has been sent photographs of injuries in both adults and children, but the newspaper said it was unable to verify how the injuries took place.

The detainees have lodged an offical complaint asking: “ With what right securities hit us and even little children and women?

“How do we know something worse won’t happen again, who is responsible for our safety?

“Some securities threaten us, how do we make sure we are safe from them?

“We are not feeling safe and we need convincing, respond as soon as possible.”

Greens immigration spokesperson Senator Sarah Hanson-Young said the government has to address the public in the wake of the alleged violence.

Senator Hanson-Young said reports that tensions had boiled over in the camp were “very concerning”.

“The government needs to start being up front about what is going on,” she said. “The minister would prefer that people were left in the dark.”

Senator Hanson-Young used the reports to ramp up calls for Wilson Security to be stripped of its contract for the Nauru centre, following its links to a corruption scandal which were revealed earlier this week.

- PNC sources