The Ambulance Service said that it had treated more than 30 people for smoke inhalation at a circus in Co Antrim on Saturday afternoon.
Ambulance staff were called to the scene by the fire brigade at around 4pm in Carrickfergus.
Initially it was believed only two individuals were affected.
But later this number escalated to 30.
At time of writing, the Ambulance Service said the incident had wound down, and that no one had required hospital treatment.