Twin pandas at a Tokyo zoo are set to be returned to China in late January, leaving none in the country for the first time in around half a century, Kyodo News reported on Monday.

The deadline for the return of Xiao Xiao and Lei Lei, which have lived at Ueno Zoological Gardens since birth, is approaching in February under a bilateral lease agreement between Tokyo and Beijing, the report said, citing a source close to the matter.

Earlier this year, four pandas at a zoo in Wakayama Prefecture were also sent back to China, leaving only the Ueno twin pandas in the country.