XI'AN, Aug. 19 (Xinhua) -- The first giant panda born through artificial fertilization in northwest China's Shaanxi Province gave birth to twins Tuesday via the same process, the Shaanxi Rare Wild Animals Rescue and Breeding Research Center said Wednesday.

    Six-year-old Lousheng delivered a male cub at 8:40 a.m. and a female cub 18 minutes later.

    The twins -- the male weighing 162 grams and the female weighing 131 grams -- are in good health, said Jin Xuelin, the center's deputy director.

    Lousheng was artificially inseminated at the end of March after it was discovered she was in heat. But it was not until 10 days before the birth that researchers knew of the pregnancy.

    Sperm from two male pandas, Sansan and Xiaoming, inseminated Lousheng, said Ma Qingyi, head of the center's veterinary hospital. "But we won't be able to tell which one is the father until the cubs undergo a DNA test," Ma said.

    "The success of Lousheng's delivery is a great step forward in our propagation technologies."

    The center in Zhouzhi County, the provincial capital of Xi'an City, is now home to 20 giant pandas, including the two new-born cubs, he said.

    About 1,590 pandas live in the wild in China, mostly in Sichuan, and the northwest provinces of Shaanxi and Gansu. Another 180 havebeen bred in captivity.