The Refugee Action Coalition says a dismissive letter from Australia's Border Force prompted the latest protests at the detention camps in Nauru.
The ABF's letter including statements, which the Coalition says are absurd, about the quality of medical conditions and education on Nauru and the option they have of moving to Cambodia.
The Coalition says Australian Wilson Security guards lashed out at the teenagers on Wednesday night, causing minor injuries.
It also says one woman was pushed over in the fracas and suffered a heart attack, while another swallowed washing powder in the aftermath of the protest.
The Australian government says guards eventually 'de-escalated' the tense situation.
It followed 18 days of daily protests at the family compound as many have waited for more than three years to have their asylum application assessed.
The Coalition says a sign of the deteriorating situation on Nauru is the graffiti now appearing on buildings in the compound.
Foreign journalists are denied access to Nauru with the government applying a US$5,000 non refundable visa application fee.
Last month, Nauru's foreign minister David Adeang told a conference in Bali that the camps were world class, with hundreds of the refugees now employed and living contentedly in the community.