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At least four children have been taken to hospital after they were affected by suspected chemical exposure at an indoor pool in Sydney.
Emergency services were called to an indoor swim centre at Prestons in the city's west just before 4pm.
9News understands a total of seven children and three adults were treated at the scene by paramedics after a suspected chemical exposure.
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Five of those have been taken to hospital.
The conditions of the children and adults are not yet known.
At least six crews from Fire and Rescue NSW (FRNSW) and NSW Ambulance are at the scene.
Some emergency responders have been spotted entering the swim centre dressed head-to-toe in hazmat suits.
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FRNSW Adam Dewberry told 2GB's Chris O'Keefe that two chemicals were mixed accidentally.
"Two chemicals related to pool chlorination and cleaning have been mixed together that shouldn't have been," he said.
"They have caused a toxic and nasty vapour."
Dewberry believes the chemicals were sodium hypochlorite and hydrochloric acid.
Thirty people have been evacuated from the centre.
Firefighters are now diluting the chemicals that have been mixed together to restore safety to the site.
More to come.
