Four people, including two young children, have been hospitalised following a gas explosion at a popular NSW holiday park.

Emergency services were called to the BIG4 Ingenia Holidays park on Norman St in Lake Conjola about 7.30am on Saturday after reports of a barbecue explosion.

NSW Ambulance said five people were assessed at the scene, with four taken to hospital, including two children under the age of five.

A man in his 30s suffered facial injuries and was flown to Wollongong Hospital in a stable condition.

A woman in her 30s sustained abdominal injuries and was taken to Shoalhaven Memorial Hospital.

Two young children suffered minor injuries and were also taken to Shoalhaven Memorial Hospital, both in a stable condition.

A fifth person did not require transport to hospital.

The outdoor kitchen at the holiday park before the explosion.The outdoor kitchen at the holiday park before the explosion. Credit: BIG4

A witness told The Australian the explosion occurred as a family holidaying at the park was preparing breakfast on the barbecues.

“I was sitting on the balcony and it was just a huge explosion,” the witness said.

“It looks like they’ve got probably gone to start it. There been a gas leak and it’s just blown up.”

Fire and Rescue NSW has been contacted for comment.