This image released August 22, 2015
courtesy of the Smithsonian's National
Zoo and Conservation Biology Institute
shows giant panda Mei Xiang in labor
Mei Xiang ("beautiful fragrance"), 17, was artificially inseminated in April with frozen semen from a male giant panda named Hui Hui that resides at the China Conservation and Research Center for the Giant Panda in Sichuan province.
Giant Panda Mei Xiang, who gave birth to twin cubs at the Smithsonian National
Zoo in Washington, is shown in a file picture from last year keeping a watchful eye
on her earlier cub Bao Bao (R) (AFP Photo/Mandel Ngan)
The zoo said Mei Xiang will spend almost all her time in her den for the next two weeks. The enclosure will be closed to provide quiet, though online "panda cams" provide a video stream of the creatures.
Mei Xiang eats a bamboo breakfast January 6, 2014, inside her glass enclosure
at the Smithsonian's National Zoo in Washington, DC (AFP Photo/Paul J. Richards)
This image released August 23, 2015 courtesy of the Smithsonian's National Zoo shows
the second of two giant panda cubs being examined by veterinarians (AFP Photo)