A school girl has been arrested after two pupils were taken to hospital following a "gas release" at a school.
More than 100 potential patients were assessed following the incident involving an aerosol at St Paul’s RC High School in Wythenshawe, Manchester.
Medics took two pupils to Wythenshawe Hospital with minor breathing difficulties.
A 13-year-old girl was later arrested and remains in custody.
The school said in a statement the premises were 'evacuated as a precaution due to the suspected discharge of an aerosol in one area'.
"The emergency services were called by the school to support the efforts being made to ensure the wellbeing of our pupils," a spokesperson added.
"All pupils have been accounted for and responded to the situation in a very mature way.
"Parents have been notified about this incident via email and text message, but, there is currently no need to collect their child early from school."
Emergency services, including a specialist hazardous area response team and advanced paramedics, were scrambled to the incident at around 12.15pm on Wednesday, 16 February.
A major incident was declared by North West Ambulance Service (NWAS) but it was stood down nearly three hours later.
Greater Manchester Police said: “Following an incident earlier today involving the release of gas from an aerosol can at a school we can confirm a 13-year-old girl has been arrested on suspicion of possession of a section 5 offensive weapon.
“She currently remains in custody.”
Firefighters from Greater Manchester Fire and Rescue Service used four breathing apparatus and gas detectors to assess the scene.
They also assisted ambulance crews in triaging those evacuated from the school.
In a statement, NWAS said: "At 12.16pm the service was called to an incident involving a release of gas at St Paul's RC High School, Wythenshawe, Greater Manchester.
"Due to the number of potential casualties and the resources needed at the scene, the trust declared a major incident.
"We sent 21 resources including emergency ambulances, our Hazardous Area Response Team (Hart), advanced paramedics, Merit doctors and volunteer services who between them assessed more than 100 potential patients.
"Of those, two were taken to Wythenshawe Hospital with breathing difficulties - none of the conditions presented to us were life-threatening."