An aging giant panda couple loaned to a Japanese zoo have been returned to China.

Ri Ri and his mate Shin Shin, both 19, were flown back to China's Sichuan province to be treated for age-related high blood pressure on September 29.

Footage shows the pair being loaded in crates onto a chartered plane at Tokyo's Narita International Airport, where hundreds of fans bid them farewell.

A day earlier, thousands of tearful locals flocked to the Ueno Zoological Gardens in Tokyo for the beloved pandas' final public viewing.

Yutaka Fukuda, head of the Ueno Zoological Gardens, said: 'It's a little sad, but the feeling of gratitude is greater. We want them to live peacefully in the environment where they were born and raised.'

Ri Ri and Shin Shin were lent to the zoo in 2011 on a 10-year lease. However, their stay was extended to 2026 due to the COVID-19 pandemic.

Japan agreed to return the panda couple to China earlier due to their deteriorating health. Their twins Xiao Xiao and Lei Lei are still at the Ueno Zoo and are the only remaining pandas there.

Panda diplomacy refers to China's practice of gifting or loaning giant pandas to other countries as a gesture of goodwill and to strengthen diplomatic ties. The tradition is said to date back to the 1950s and remains a key element of China's modern foreign policy.