CNN  — 

Five young children were found dead in a locked freezer in a South African town.

The children, ranging in age from 3 to 7, were discovered Tuesday evening by their grandmother in Kakamas, in northwest South Africa. They apparently suffocated inside an old freezer in the yard, police said. The children were believed to have been playing in the freezer when they accidentally got locked inside.

Police have begun an investigation into the deaths of the children, who were cousins.