Giant pandas Tian Tian and Yang Guang are to have their indoor show dens closed to visitors from Friday as tension mounts over a possible pregnancy.

But Edinburgh Zoo said both pandas' outdoor viewing areas will remain fully open to visitors during this time.

A spokesman for the zoo said: "Although both pandas can choose to be off show if they wish, we will encourage Yang Guang outside with scatter feeds as often as we can.

"You may also see Tian Tian when she goes outside.We apologise for any inconvenience to our visitors, but our animal teams and veterinarians are working hard to respond to Tian Tian's signals and create the best environment for her.

"Although she is content and comfortable, this is a critical time in her potential pregnancy, and like last year she is showing sensitivity to noise."

If Tian Tian does give birth in late August or early September it is likely the zoo will close the whole Panda enclosure for several weeks.

Until they know if Tian Tian is pregnant the zoo will not be issuing advance panda-enclosure tickets for September.