Giant pandas Lun Lun and Yang Yang, who were kept at Zoo Atlanta in the United States, along with their twin offspring Ya Lun and Xi Lun, arrived safely in Chengdu, Sichuan province on Sunday evening, the Chengdu Research Base of Giant Panda Breeding said.

Veterinarians confirmed that the four giant pandas are in good health and were smoothly transported to the research base under the care of a team of veterinary and feeding management experts, where they will undergo quarantine for about a month.

According to the China-US giant panda international conservation cooperation agreement, the two giant pandas Lun Lun and Yang Yang had traveled to Zoo Atlanta in 1999 to reside there.

During their stay, they received meticulous care and healthy rearing and gave birth to seven baby pandas, achieving the best results in international giant panda breeding cooperation between China and countries in Europe and the US, according to the Chengdu base.

Ya Lun and Xi Lun were born in the US in 2016.

As a result of the international giant panda cooperation project, both China and the US have engaged in various forms of cooperation, including giant panda breeding and rearing, behavioral training, preventive veterinary medicine and conservation education.

These outcomes play an important role in enhancing the technicalities of giant panda conservation research and promoting the development of giant panda conservation efforts, as well as making positive contributions to mutual understanding and friendship between people in China and the US, the Chengdu base said.