Investigators say that they are now treating as "suspicious" a fire which ripped through an Invercargill school on Thursday morning.
Firefighters put out the blaze at James Hargest College's senior campus at about 7.30am after battling it for more than an hour and a half.
They say at least four classrooms and one vehicle have been destroyed and several others are severely damaged.
Senior Sergeant Dave Raynes of the Invercargill police, says if anyone saw any suspicious activity around the school early this morning, they should contact the police.
Deputy principal Al Pannett told Summer Report the classrooms were in a block that was being refurbished at the senior campus in Layard Street.
The cause of the fire is not yet known, but he said it could be connected to a recent break-in or a smaller fire a month ago.
The college has about 1950 students and Mr Pannett said the destruction of the classrooms will be disruptive when the school year begins.