BRENTWOOD, Mo. (AP) — Authorities say an ammonia leak at a suburban St. Louis recreation complex sent eight people to hospitals.

Brentwood City Administrator Bola Akande says none of the injuries was life-threatening.

The leak was in a room with a refrigeration system for the complex’s ice rink. Ammonia is used as a refrigerant at many ice rinks.

Authorities say the complex was evacuated after the leak was reported about 11:30 a.m., and the site was declared safe within two hours.

The cause of the leak wasn’t clear.