A boy was in critical condition after his arm was caught in a swimming pool suction pump Yangtze Evening News reported on Friday.

The 7-year-old boy from Suzhou, Jiangsu province, was trying to retrieve a toy on Wednesday from the pump, which did not have a safety cover, when his arm was trapped and he was submerged for about four minutes.

He was freed and rushed to hospital where he remains in a critical condition.

Police are investigating the incident.