The birth of a giant panda cub at Tokyo's Ueno Zoo on Monday was toasted in Japan.

The 11-year-old Shin Shin, which means "truth", was removed from public viewing in mid-May after she began showing signs of pregnancy, including loss of appetite and increased lethargy.

Tokyo Governor Yuriko Koike congratulated Shin Shin on her successful delivery.

Shin Shin and her mate Ri Ri, which means "power", have been on loan from China since February 2011. They were ready for display shortly after the devastating earthquake and tsunami on March 11, 2011, bringing some much-needed joy to Japanese fans.

In 2012 Shin Shin and Ri Ri, also 11, had a cub, the first panda born at Ueno Zoo in 24 years. It was greeted with widespread excitement. But the cub died from pneumonia six days after birth.

Shin Shin also showed signs of pregnancy in 2013 but it turned out to be a false alarm. Panda pregnancies are relatively rare in captivity and outside of China.

Japan returned three pandas born and raised in Japan to China on June 6 under a standard agreement to improve the breeding success of the rare animals.

The 6-year-old twins and their 4-year-old sister that had been living at Japan's Wakayama Adventure World are now at the Chengdu Research Base of Giant Panda Breeding, where they are being quarantined for a month as they acclimatize to their new home before the public can see them.

Wakayama Adventure World and the Chengdu base have been working together on panda breeding research since 1994. The program has led to the births of 15 pandas, eight of whom have already returned to China, according to Xinhua.

caihong@chinadaily.com.cn