A Papakura teacher was injured when two people tried to take a student from Kelvin Road School, triggering a school-wide lockdown on Wednesday afternoon.

Emergency services were called when two people, known to one of the pupils, "attempted to take the student out of the school grounds", a police spokeswoman said.

A staff member received minor injuries trying to stop the pair, she said.

Police were called to the South Auckland school shortly after 1.15pm.

School management posted on Facebook that the lockdown lasted only a short time.

"Rest assured everyone is safe," parents and caregivers were told.

Police were speaking with a number of people about the incident and were making inquiries, the spokeswoman said.

Last month a Hamilton high school was put into lockdown after a youth "known to the school" escaped Oranga Tamariki supervision and made their way there.

Fraser High School principal Virginia Crawford told parents the young person presented a "real and present danger to our students and staff".

As soon as the school was informed the youth had absconded, police were called and the school went into lockdown.

Staff and students remained in lockdown as police engaged with the young person, who was then taken back to Oranga Tamariki's care.