"It was a very special moment that we had twins, so we contributed to preserve this endangered species," told Reuters Madrid zoo veterinary Eva Martinez.
The pair, whose sex is yet to be determined, were born on Monday (September 6). They are the fifth and sixth cubs of Madrid's female panda Hua Zui Ba and her partner Bing Xing, the zoo said.
Technicians from China's Chengdu panda breeding base and local veterinarians carried out the first neonatal examination on Tuesday in which the umbilical cord was tied and disinfected.
Baby pandas were weighed, with 171.4 and 137.4 grams, respectively. As for the sex, it is still an unknown as the sexual characteristics are not yet well defined.
It will not be until approximately two and a half months later, when they are usually strong enough, when they can be seen and a name with Spanish-Chinese symbolism will be chosen, which will be voted on through the Madrid Zoo's social networks.
In July, Chinese conservationists announced they no longer considered pandas to be an endangered species, upgrading their status a notch to vulnerable.
The International Union for Conservation of Nature made a similar change to its classification in 2016.