Skype users had problems logging in and receiving messages, with the service down across much of the US on Wednesday morning. Northeastern states were the most affected, according to Down Detector. Services started returning after about an hour.

Much of southern England, Spain, Japan and Ecuador were also facing problems, as well as Moscow and St. Petersburg in Russia.

The company addressed the messaging issues on its blog, describing it as “an incident” with its service.

“Users could see delays, or failures in chat message delivery and group chat operations. Our engineers are on it and we hope to resolve the issue soon. We apologize for problems this may have caused to our customers,” Jagadish Harihara wrote on the Skype blog.

@bondskew I think the outage is just affecting Skype, not SfB, That outage map looks like the zombie apocalypse — Edward Kinsley (@BitFlippr) November 23, 2016

The problems appeared to have started at 10:38am ET and began being resolved about an hour later.

Skype is estimated to have some 74 million users worldwide. The online chat, voice and video calling service was developed in Estonia in 2003, and bought out by Microsoft in 2011.

The messaging service had problems on three days earlier in November, on the 14th, 17th and 18th.

Is @Skype down again? I can't seem to login. This is happening too frequently lately. — Brett Koenig (@brett9897) November 23, 2016

"The issue has been mitigated," Harihara wrote in an update just after 16:00 GMT.