AP Photo/ Vino Wong

Published: Jul 15, 2013 6:39 PM EDT

ATLANTA (AP) - A spokeswoman for Zoo Atlanta says the zoo's pregnant giant panda, Lun Lun, has given birth to twins.
    
Zoo Atlanta spokeswoman Keisha Hines said Monday that officials weren't immediately sure of the cubs' genders. Lun Lun went into labor Monday afternoon and gave birth hours later.
    
An ultrasound on June 30 determined Lun Lun was pregnant with her fourth cub. Zoo officials said they were surprised to see her deliver a fifth cub, and Hines says it's the first twin panda birth in Zoo Atlanta history.
    
Officials have said Lun Lun's cub would be the first giant panda to be born in the U.S. this year.
    
Lun Lun was artificially inseminated in March and has been under 24-hour observation by a camera providing a live video feed.
    
---
    
Online: www.zooatlanta.org/pandacam

(Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)