Swimmers have been evacuated by police from a busy waterpark after some suffered nausea and eye and throat irritation.
Paramedics rushed to Waterworld in Festival Way, Stoke-on-Trent as it was being emptied by officers during the half-term swim session on Wednesday.
A number of people have been reported unwell, according to West Midlands Ambulance Service.
The cause of the illnesses is not yet clear.
“Visitors have reported eye and throat irritation and nausea. The building has been evacuated.
“The emergency services have the incident in hand and urge members of the public to avoid the area.”
Waterworld, which attracts 400,000 visitors per year, is a tropical-themed water park offering a wave pool, slides, rides and flumes and a weekly aqua disco.
Staffordshire Fire and Rescue Service are also on the scene.
They said: “A number of crews are currently in attendance at the waterpark carrying out an assessment.”
West Midlands Ambulance Service tweeted: “We have a number of ambulances & specialist resources at Waterworld, Stoke-on-Trent with @StaffsFire and @StaffsPolice.
“We’re assessing a number of people who report feeling unwell. Please avoid the area to allow 999 staff to deal with the incident. More to follow.”
Waterworld has been approached for comment.