CAPE TOWN, September 14 -- Three children were found dead in an old refrigerator in the township of Atamelang, the North West Province, police said on Saturday.

The grandfather of one of the children found the bodies inside the refrigerator on Friday.

The children, aged three and four, were last seen playing outside their home on Thursday, said police spokesman Sergeant Kealeboga Molale.

It was believed that the children locked themselves inside the refrigerator while playing, said Cape Town-based news outlet Eyewitness News.

"Parents and community members tried to look for them but failed, " said Molale.

"The community was alerted and helped to search but that did not yield any results. On Friday, at about half past 12, the grandfather of one of the victims found them in a kraal where the old refrigerator was stored."

Investigation is under way to find the real cause of deaths, according to Molale.