It's double trouble for the National Zoo in Washington DC after its adult female panda gave birth to twins.
The cubs arrived about five hours apart. Panda mom Mei Xiang gave birth to the first cub at 5:35pm and a second at 10:07pm, the zoo said. If the cubs survive, they would be the 17-year-old panda's third and fourth surviving offspring.
Mei Xiang's first cub, Tai Shan, was born in 2005 and returned to China in 2010. Her second cub, Bao Bao, turns 2-years-old Sunday and still lives at the zoo.
The new additions mean that for the first time the zoo has five pandas in residence.
In addition to Bao Bao, Mei Xiang and the new cubs, the zoo is also home to an adult male panda named Tian Tian.
Staff say both newborns appear to be healthy.
