A giant panda at the Smithsonian's National Zoo in Washington has given birth to her third cub, a female.

The zoo said Mei Xiang gave birth at 5:32 p.m. Friday, two hours after her water broke. Zoo officials said panda team heard the cub vocalize and said Mei Xiang picked the cub up immediately and began cradling and caring for it.

"WE HAVE A CUB!! Born at 5:32 p.m. this evening," the zoo tweeted.

Dennis Kelly, director of the National Zoo, said, "I'm glued to the new panda cams and thrilled to hear the squeals, which appear healthy, of our newborn cub."

The zoo has been on round-the-clock panda watch since Aug. 7, when Mei Xiang began showing behavioral changes consistent with a pregnancy or pseudopregnancy.

A Chinese panda expert performed artificial inseminations on Mei Xiang on March 30 after she failed to breed naturally with male panda Tian Tian.

Mei Xiang had previously given birth to two cubs. Tai Shan was born in 2005 and a week-old cub died last September.