A pair of giant pandas at Tokyo's Ueno Zoological Gardens have departed for China to spend the rest of their life in their motherland.

Male Ri Ri and female Shin Shin left in the early hours of Sunday. They had spent more than 13 years at the zoo, after coming from China in February 2011.

Dozens of fans gathered outside the gate of the zoo to take photos and wave farewell.

The pandas, at the advanced age of 19, will be treated for high blood pressure in China.

Zoo officials said the pair were moved to transportation cages about one hour before departure, but they remained calm and ate bamboo handed over by the staff.

The officials added that the animals also drank water and ate apples. After that, the staff carefully put the cages onto a truck.

They are scheduled to arrive at the China Conservation and Research Center for the Giant Panda later in the day, after departing from Narita Airport near Tokyo on a special flight.

The zoo's head, Fukuda Yutaka, said he misses the pandas, but expressed gratitude to them for making many people smile. He said he wishes them good health and a long life in China.