CHENGDU, July 8 (Xinhua) -- Weighing over 200 grams each, a pair of male-female panda twins were born in Chengdu, capital of southwest China's Sichuan Province, local authorities said Monday.

They are believed to be the heaviest captive-bred panda twins born in the world, according to the Chengdu Research Base of Giant Panda Breeding.

The male giant panda cub weighs 211.6 grams and the female 209 grams. They were born at the base on Saturday morning and are in stable condition.

The average birth weight of panda cubs is around 150 grams. It is rare to see both twin cubs weigh over 200 grams each at birth, experts said.

Their mother Po was born at the Zoo Atlanta in November 2010 and was named after the hit Hollywood animated blockbuster "Kung Fu Panda."

Po's water broke at 4:47 a.m. Saturday. This was her first delivery, but she held and licked her cubs soon after, which showed her strong sense of maternity.

As of Monday, a total of 298 giant panda cubs have been born at the Chengdu research base.

The giant panda was scientifically discovered 150 years ago and named in the city of Ya'an, Sichuan. It remains one of the world's most endangered species.

The number of captive pandas was 548 globally as of last November. Fewer than 2,000 pandas live in the wild, mostly in the provinces of Sichuan and Shaanxi.