Phone service has been restored to the majority of Shaw customers after an outage Saturday morning.

The company said the problem was concentrated around Calgary and Hamilton, Ont., and impacted 311 service. Many people reported having no dial tone.

Shaw says the outage did not affect 911 service.

"The vast majority of our customers should now have full phone accessibility," Shaw said in a tweet around 2 p.m. MT. "Please stay tuned as we complete full restoration services."

On the company's website, residents of Cochrane, Okotoks, Airdrie and Edmonton, as well as several Ontario cities, posted to say they were also experiencing disrupted service.

It's not clear at this point what caused the outage.

This is the second time in two weeks that phone service in Calgary has been disrupted.

An outage on the Telus network cut off 911 service on Sept. 19.