Four cheetah cubs have been born at Prague Zoo.

Scientists say every cub is critical to saving the species, which is threatened with extinction in the wild. Cheetahs are the fastest animals on land.

The zoo said the four cubs were born on November 21. They have not been named yet and their sexes are not known.

They have survived the most critical period after the birth and their mother, three-year-old Savannah, is taking good care of them.

It was the first birth for Savannah, who lives with brothers Ben and Jerry. The zoo believes Ben is likely to be the father.

The zoo announced the birth today, International Cheetah Day.