A rare giant panda has given birth to twins in China, the first pair of the endangered species born in the world this year, conservation workers told state media Sunday.

They were born to a panda named Haizi at the Wolong Nature Reserve in China's southwest Sichuan province on Saturday evening, according to the Xinhua news agency.

The first cub arrived at 4:54 pm (0954 GMT) and the second 10 minutes later, said workers at the China Conservation and Research Centre for the Giant Panda on the reserve.

The mother is still holding the first cub in her arms so staff have been unable to weigh it or determine its gender. But they said it should be healthy, given its size and the sounds it has been making.

The second cub is a female and weighs 79.2 grams (just under three ounces), the staff said, according to Xinhua.

Haizi became pregnant after mating with males Bai Yang and Yi Bao in March -- most giant pandas are not good breeders when in captivity.

Fewer than 1,600 pandas remain in the wild, mainly in Sichuan, with around 300 in captivity around the world, the majority in China.