Users of Facebook, Instagram and Messenger have been reporting problems since 2 p.m. Wednesday.
According to the specialist site Down Detector, problems began to appear shortly after 2 p.m. on Messenger, Facebook and Instagram.
In less than two hours, nearly 10,000 people reported an issue with Instagram on the Down Detector site, while 5,000 people reported issues on Facebook and Messenger.
Many Internet users indicate that they are unable to read the messages received, although they are able to send some.
The problems appear to be widespread around the world. Internet users from Switzerland, Egypt, the United States, Mexico, France and Canada reported difficulties.
The blackout comes less than a month after the historic blackout that hit social networks Facebook, Instagram, WhatsApp and Messenger, for nearly seven hours.
The problems were caused by a faulty configuration change of its servers.
More details to come.