After giving birth to the country's first rare white tiger cub, tiger couple Raj and Pori have now parents of four more white cubs.

Pori delivered four healthy cubs weighing between 800-900 grams each around Saturday evening at Chittagong Zoo, said Dr Shahadat Hossain Shuvo, deputy curator of the zoo.

With this the total number of tigers in Chittagong Zoo has reached 16 now, he said.

On July 19, 2018, Royal Bengal Tigers Raj and Pori had given birth to the country's first white tiger cub who was named 'Shubhra'.

"The cubs are drinking their mother's milk and living with her inside the cage. Within seven days their sex can be identified," said Dr Shahadat Hossain Shuvo.

The white tiger or bleached tiger is a leucistic pigmentation variant of the Bengal tiger, Siberian tiger and hybrids between the two. For a white Bengal tiger to be born, both parents must carry the unusual gene for white colouring, which only happens naturally about once in 10,000 births. Dark-striped white tigers are well-documented in the Bengal tiger subspecies (Panthera tigris) as well as have been reported in several other subspecies.