A baby giant panda was born at a Tokyo zoo on Thursday, in a rare success for Japan's captive breeding programme, a zoo official said.

The as-yet unnamed infant is Ueno Zoo's first baby panda for 24 years, and its first ever from natural sexual intercourse, she told AFP.

"The baby was born around noon today, but we have no further details as our keepers are taking care of the pandas," she said.

The zoo had suspended public viewing of the "possibly pregnant" giant panda Shin Shin on Saturday after keepers noticed she had became nervous about noise and light.

Shin Shin and her mate Ri Ri were confirmed to have mated twice in late March, and the female panda's condition, including her hormone level and a loss of appetite for about two weeks, had suggested she was pregnant.

The couple were leased from China last year to the zoo operated by the Tokyo Metropolitan government at an annual cost of about a million dollars.

In Japan, a total of 16 giant pandas have been born, the Yomiuri Shimbun reported.

In Beijing, Chinese foreign ministry spokesman Liu Weimin told reporters the new arrival was good news.

"The giant pandas are messengers of friendship," he said."We hope that people-to-people sentiment and overall relations between China and Japan can be promoted because of the birth of the cub."