Two-year-old giant panda twins Jia Panpan and Jia Yueyue play together during their 2nd birthday celebration at the Toronto Zoo in Toronto, Canada, Oct. 13, 2017. The Toronto Zoo hosted the 2nd birthday celebration for the first Canadian-born giant panda twins Jia Panpan (meaning Canadian Hope) and Jia Yueyue (meaning Canadian Joy) on Friday. The female giant panda Er Shun from China gave birth to the twins in Toronto Zoo on Oct. 13, 2015. (Xinhua/Zou Zheng)

  
Canadian-born panda twins, Jia Panpan and Jia Yueyue, flew to Chengdu, capital of southwest China's Sichuan Province, early Sunday morning.

The twins will be kept in quarantine for a month at the Chengdu Research Base of Giant Panda Breeding.

The twin cubs were born at the Toronto Zoo on Oct. 13, 2015. Their parents -- female panda Er Shun and male panda Da Mao -- were brought to Toronto in 2013 as part of a loan agreement between China and Canada. They will stay there until 2023.

The research base has established giant panda cooperation with 17 countries and regions since 1994. Currently, it is carrying out long-term cooperative programs for giant panda research and breeding with seven countries.