Emergency services are heading to South End School in Carterton after a number of students have fallen sick.
The school said a strong smell was discovered in the playground at about 1pm and several students have reported feeling dizzy and unwell.
One student told staff they had seen a plane dropping a substance near the school, the school said in a Facebook post.
Staff are monitoring the students closely.
No students are allowed to leave the school grounds and nobody is allowed to enter the school until emergency services have investigated the substance.
Wellington Free Ambulance Service has an area manager at South End school assessing the situation, plus four ambulances attending to the students
Fire services said they sent four crews from Wairarapa to an incident in Carterton, with support vehicles from Wellington and Hutt Valley.
South End School is a primary school with 140 students from year 1 to year 8.
More to come.
i,m a tudent of south end school and i was so scared
Poisoning kids now. Dont worry C.A.A. will do a good cover up for the pilot. It is just a bit of collateral damage for one of their boys trying to earn a living. Apparently” you can do what you like with the stuff as long as you can say it was an accident ” . According to C.A.A. Health and Safety Unit Manager. Tell them to make sure it was not mixed extra strength cause it causes permanent damage.