A spokeswoman for Zoo Atlanta says a giant panda named Lun Lun has given birth to twins.
Keisha Hines said Lun Lun went into labor Monday afternoon and gave birth at 6:21 p.m. EDT, surprising zookeepers with the first twins born at Zoo Atlanta.
"We have twins!" the zoo trumpeted on its website.
An ultrasound on June 30 determined Lun Lun was pregnant with her fourth cub. Hines says zookeepers weren't expecting a pair.
Lun Lun had been artificially inseminated in March and has been under 24-hour observation by a camera providing a live video feed.
Zookeepers aren't immediately sure of the genders of the cubs, and there was no immediate update on the condition of the mother or offspring.