One injured, one arrested, police investigating after suspected stabbing at Tawa College, Wellington

Tawa College went into lockdown this afternoon. Photo / Supplied

A Tawa College student has described the aftermath of a suspected stabbing that sent the school into an hour-long lockdown.

One person has been arrested and another taken to hospital with serious injuries after the incident in Wellington.

A student, who did not want to be named, said he and his classmates had to turn off the lights, draw the curtains and hide under their desks for nearly an hour this afternoon.

The victim has been taken to hospital with serious injuries and police are investigating following the incident, which happened shortly after 2pm.

The student told NZME he was heading to class after lunch with his friends when they heard what had happened.

"A couple of students just came up and said, like, 'someone's been stabbed around A block,'" he said.

They passed the area on their way to class and saw hundreds of students gathered around the stairs, as well as ambulances.

When they had been sitting in class for a few minutes the bell started ringing.

Students were told "go to class, get on the ground, turn the lights off, shut the curtains", he said.

They remained in lockdown from about 2.20pm to 3.30pm, he said.

An alert sent to parents stated the school was in lockdown shortly before 2.30pm, and asked parents not to contact the school.

"Tawa College has been advised to go into lockdown as a precautionary measure," the alert said.

"Please refrain from contacting any staff at the school, as this could lead to distraction of their primary focus, which is caring for our students."

The boy's father said he and his wife knew their son was safe because he had been keeping them informed through a family Snapchat group.

"All his classmates are doing the same," the parent said.

"It feels like this was targeted rather than random which is in some ways better than someone just walking in off the street for no reason."

He said the school had kept parents well informed.

NZME understands about 2.50pm students were allowed to sit on chairs and talk, though the lights in the classrooms remained off. However, they were subsequently told to get back under their desks - before later being let out.

A police spokeswoman said they were called to Duncan St, where the school is, about 2.15pm, after reports of an assault.

One person was taken to hospital with serious injuries, she said.

The other person involved was taken into custody.

"Police believe this is an isolated incident and poses no threat to the wider community.

"Contrary to other reports, this was not believed to be gang related," she said.

"Police are making initial inquiries to establish what has happened and a scene examination is currently underway."

Parents received another alert about 3.45pm confirming the school was out of lockdown.

"All students, staff, and persons on-site are safely accounted for," the alert said.

"Everyone did extremely well and responded to instructions."

A Wellington Hospital spokesman said the injured person was being assessed in the hospital's emergency department.