Two critically endangered Amur leopard cubs have been born at a Missouri zoo.

Officials at the Saint Louis Zoo say it's an important contribution to the population of one of the most endangered big cats in the world with only about 100 remaining in the wild.

The pair was born on August 13. They don't know the sexes yet but hope to give them a check up in the coming weeks.

Officials say this is the second litter for 7-year-old parents Dot and Samson and so far everyone is doing well.

The cubs aren't in public view just yet. The zoo says it will be several months before that happens, at the age when cubs would naturally leave the den with their mother.