Five Pallas's cat kittens go on display at Japan's Kobe Animal Kingdom

Five young Pallas's cats have gone on public display at Kobe Animal Kingdom in Japan, the zoo said.

The four males and one female were all born at the facility in May. The zoo said they weighed around 150 grams at birth but now weigh more than one kilo and are starting to eat solid food, including chicken and horse meat.

Pallas's cats are known for their sullen facial expressions and are sometimes dubbed the world's grumpiest feline. The Kobe zoo said the animals are believed to be one of the oldest living cat species, are native to dry, rocky areas of Central Asia and are not commonly displayed at zoos because they are relatively sensitive to infections.

The zoo said it hoped people would come to see the kittens healthy, playing and sleeping.