A pair of female twin pandas is born in Chengdu Research Base of Giant Panda Breeding on September 16, 2015. [Photo/chinadaily.com.cn]

The giant panda breeding base in the southwestern city of Chengdu welcomed the sixth twin pandas of this year on Wednesday morning.

Mother panda, who is called "Congratulations", gave birth to the female twin at about 11am with the elder panda weighing 152 grams and the younger 150 grams. Initial signs show that the mother and the two babies are safe and healthy.

Six pair, three male and three female twins, have been born in Chengdu Research Base of Giant Panda Breeding in Southwest China's Sichuan province since June.