An emergency services call out to Te Puna Wai youth justice facility last night was due to a group of girls huffing aerosol cans, police have confirmed.
Two of the girls were taken from the facility in Rolleston to Christchurch Hospital after the incident just after 6.30pm.
Fire, Police and St John Ambulance were all called to the scene.
A Police spokesperson said officers stood in to help security at entrances, while emergency services moved residents in and out.
St John staff said they received reports of several people breathing in some chemicals at the facility. They wouldn't comment further on the incident, saying it was a matter for Corrections.
Corrections in turn passed the matter on to Ministry of Social Development for comment.
The ministry confirmed St John was called but wouldn't comment further.
Te Puna Wai is the only youth justice unit in the South Island.