The men ducked and took off to the Mathewson farm, where they sought help from Mrs Mathewson.
She was home alone so she contacted her husband on the radio and asked him to come down off the farm.
The couple rang police and alerted the school.
She believed a tattooed, shirtless man, in his 20s had been arrested at Te Awaiti.
A spokesman from the Wellington district command centre confirmed a man had been arrested shortly before 5pm and was being interviewed by police.
He could not confirm if the man had a gun when he was arrested but said the public could be reassured all was safe.