Seven people suffered minor injuries from an explosion at a Hamilton Fonterra plant, and were treated at Waikato Hospital.

Fonterra said in a written statement that the explosion happened at a print oven at Canpac in Te Rapa about 1pm on Thursday.

The seven men, aged between 40 and 52, had minor to multiple injuries, and were treated and discharged from hospital.

Fonterra has refused to make any further comment.