BERLIN (AP) — A Berlin zoo is celebrating the birth of four rare Sumatran tiger cubs earlier this month.

The Tierpark Berlin zoo said Friday that 7-year-old Mayang gave birth to two female and two male cubs Aug 4. It is her first litter with 10-year-old male Harfan.

The zoo said the cubs are about "bunny size" and will remain secluded from the public until the end of October.

Sumatran tigers are regarded by conservationists as critically endangered. About 350 to 450 animals exist in the wild.

Zoo director Andreas Knieriem said the cubs are genetically valuable to European zoos trying to prevent the extinction of the Sumatran tiger.