One of the giant panda cubs born on at the Smithsonian's National Zoo in Washington, DC is being examines by veterinarians in this image taken on August 22, 2015. [Photo/Agencies]

WASHINGTON - The National Zoo's giant panda Mei Xiang gave birth to a cub on Saturday, the zoo said.

Earlier this week, veterinarians detected a 1.6-inch (4-cm) fetus during an ultrasound of Mei Xiang, who is a star tourist draw in the U.S. capital.

Mei Xiang previously has given birth to two surviving cubs: Tai Shan in 2005 and Bao Bao in 2013.