Ian Rintoul from the Refugee Action Coalition says the group have been at the detention centre since December last year.
Mr Rintoul says the five are seeking answers over their continued detention, particular given the climate of uncertainty after the federal government's recent visa changes.
The federal government last week announced it would halt the processing of asylum claims from Sri Lanka and Afghanistan, citing 'evolving circumstance' in both countries.
The Iraqi detainees are upset by the changes, and worried the government may change rules for Iraqis Mr Rintoul says.
A large group of asylum seekers in Sydney's Villawood detention centre called off a hunger strike earlier this week, following medical advice.
The men, all from Afghanistan and Sri Lanka, had been protesting the government's changes.
