A schoolgirl has been arrested after two students and a staff member were stabbed at a school in Manchester.

Students were put into lockdown and told not to leave their classrooms after emergency services were called to the Co-op academy in Blackley on Tuesday morning.

Greater Manchester police said a girl was arrested at the scene and that the injuries sustained by the two students, a boy and a girl both aged 14, and a 27-year-old male staff member, were consistent with stab wounds but were “non-serious”.

A GMP spokesperson said: “Officers are currently responding to an incident at a school [in] Blackley where a schoolgirl has been arrested. Three people have been injured. However, injuries aren’t believed to be serious at this time. Emergency services remain on scene and we are supporting the school.”

GMP later said that the detained student had been “arrested on suspicion of section 18 assault and remains in custody for questioning at this time. Officers are not looking for anyone else in connection with this incident.”

Within an hour of the stabbing, a large crowd of students, parents and passersby had gathered outside the school.

Numerous parents said they had not been told anything by the school and had been forced to piece together what had happened from texts and calls from their children as they were kept in their classrooms.

One parent described the scene as “chaos” when they arrived and said they were yet to be told any details.

In a message sent to parents, the school stated that an “incident” had taken place but everyone was safe.

The message read: “We can confirm that everyone is safe and the incident has been contained. However, we have made the decision to close the school for the remainder of the day. We are speaking with parents and carers to obtain permission for children to leave.

“If we haven’t yet spoken with you, please contact your child through their mobile phone or send an Arbor message. Once a member of staff has seen and verified this permission, students will be allowed to leave the site.”

Ch Insp Jon Shilvock said: “We understand that this incident will have caused concern to pupils, staff and the wider school community.

“The incident was swiftly and quickly dealt with by staff before officers attended to arrest the girl. There is believed to be no wider threat at this time, and we thank everyone for their support as emergency services dealt with this.

“We are not looking for anyone further in connection with this incident. Officers will remain at the school and within the area to provide a visible presence and community reassurance.”