Ten patients have been taken to hospital after falling ill at a Wairarapa primary school this afternoon, a Wellington Free Ambulance spokesperson says.
The mayor of Carterton John Booth said parents had an anxious wait as children at South End School in Carterton went through a decontamination process today.
Students started vomiting after a pungent smell of sulphur was detected in the air at about 1pm.
All 10 patients taken to Wairarapa hospital have been discharged.
The school has been in lockdown since 3pm after a plane nearby dropped an unknown substance, causing multiple children to feel ill.
An earlier post on social media by the school says one student saw a plane, with 'stuff' coming out, which teachers have assumed to be fertiliser.
The decontamination process has started, with all 107 pupils and staff leaving the school grounds needing to be washed down before they can leave.