Updated

Berlin's Tierpark zoo says a baby polar bear born last month has died, less than a year after its mother lost another cub.

The zoo said the cub, which hadn't been named, appeared healthy on Monday but zookeepers found it dead when they checked a surveillance camera on Tuesday. It said that an autopsy is being carried out on the cub, which was 26 days old.

Tonja's first cub, Fritz, died of unknown causes in March at the age of four months.

The mortality rate for young polar bears is about 50 percent and can be even higher during the first 10 days.