More than 40 people have been injured after getting caught in a giant wave in a swimming pool full of people.

Authorities have blamed malfunctioning equipment for the sudden tidal wave in the theme park pool.

The South China Morning Post said Monday’s incident happened at Yulong Shuiyun Water Amusement Park, in the city of Longjing.

Video clips of the incident show a sudden three-metre wave overwhelming dozens of swimmers in a large pool at the park. Everyone in the pool, including screaming children and families, had to swim for their lives.

Some of the 44 people injured suffered fractured ribs after getting caught in the pool tsunami. According to a government notice, five people were still being treated in hospital for injuries, but were in stable conditions.

“The incident was caused by a power cut that damaged electronic equipment in the tsunami pool control room, which led to the waves in the tsunami pool becoming too big and injuring people,” the notice said.

There were initial reports that the accident happened after a drunk worker dialled the wave pool’s controls up to full speed. But they have been denied.

A theme park worker told Beijing Time that an “accidental breakdown in machinery” was to blame.

“Online rumours say that a worker wrongly operated the controls, but in reality it was a problem with the equipment,” the employee said.

The tsunami pool has been closed while the accident is investigated.