Officials at the Wroclaw Zoo in the southwestern Polish city of Wroclaw said four Sumatran tiger cubs were born in July, but they have only just revealed the news over fears they may not survive.

A Polish zoo is celebrating the arrival of four Sumatran tiger cubs, announcing their birth Friday after keeping it a closely-guarded secret for weeks due to fears they may not survive.

Endangered Sumatran tiger cubs born at Poland zoo Video from the Wroclaw Zoo in Poland shows the four bright-eyed cubs growing and getting stronger as they readied for their public debut.

Four Sumatran tiger cubs are seen Thursday at the Wroclaw zoo, which is celebrating the birth of the critically endangered predators, in Wroclaw, Poland.

Poland zoo celebrates Sumatran tiger cubs Four Sumatran tiger cubs are seen Thursday at the zoo, which is celebrating the birth of the critically endangered predators, in Wroclaw, Poland.

In this photo released by ZOO Wroclaw, Four Sumatran tiger cubs are seen at the Wroclaw zoo, which is celebrating the birth of the critically endangered predators, in Wrocław, Poland, Thursday ...