BEIJING (AP) — China has announced the birth of extremely rare panda triplets in a further success for the country’s artificial breeding program.

The official China News Service said Tuesday the three cubs were born July 29 but that breeders had delayed an announcement until they were sure all three would survive.

It said the mother, Ju Xiao, and the three as-yet-unnamed cubs are healthy. Photos showed the three sleeping and standing in their incubator, their bodies pink and mostly hairless.

There are about 1,600 giant pandas in the wild, where they are critically endangered due to loss of habitat and low birth rates. More than 300 live in captivity, mostly in China’s breeding programs.