The tiny cub died in the Oji Zoo in Kobe either from overly affectionate hugging from its mother or from not drinking enough milk, The Yomiuri Shimbun reported.
A keeper noticed in the early afternoon Friday that the baby panda's cries were weakening. The cub's death was confirmed an hour later at around 1:50 p.m.
The panda was born about 7.5 inches long and weighed less than 3 ounces after artificial insemination of mother Dan Dan from her panda partner Xing Xing. They are both 12 years old.