HALIFAX -- Many Atlantic Canadians lost the use of their cellular phones for much of Friday, as a widespread outage hampered emergency communications, airports and other services.

Bell called it a "major service outage" affecting internet, TV, wireless and landline phones, with landline 911 service intermittent.

Flights were delayed at multiple airports, some consumers couldn't use their debit and credit cards, and the TD bank said some branches in the region were "temporarily" closed.

By 3:30 p.m., the telecommunications firms started reporting that cellular service was coming back.

"The wireless service interruption affecting some regions of Atlantic Canada is being resolved, and service to Telus and Koodo customers is being restored," wrote Telus spokesman Richard Gilhooley in an email.

"We apologize for any inconvenience this incident may have caused."

The situation prompted emergency services in St. John's, N.L., Saint John, N.B., and other Atlantic cities to deploy emergency vehicles at strategic locations for people who couldn't call ambulances using normal methods.

Telus said on its web site that a "possible fibre cut on Bell network" was to blame.

In St. John's, N.L., Lauren Halliday said the outage came at a particularly bad time for her family: her sister is about to give birth.

"My sister is supposed to have a baby today or tomorrow so we were kind of sweating about that, making sure that she had a car to get to the hospital and stuff. And then I tried to make a few phone calls and nothing would go through," she said Friday.

A spokeswoman with Rogers and Fido said its cellular network was not affected. Eastlink said in a statement "an interruption impacting our network partners that may affect your ability to place calls."

Halifax Stanfield airport said some flights were affected, and Air Canada said computer issues were impacting flights at multiple Canadian airports. WestJet said its Moncton call centre is "offline," and asked customers to call later unless the matter was urgent.

The outage appeared to be affecting emergency communications in some parts of the region, and people are being advised to try non-emergency numbers to contact emergency services if 911 doesn't work.

It isn't the first time a damaged cable has suddenly sliced normal telecommunications service in the region.

In the fall of 2011, Bell Aliant said a cut fibre optic line in northern New Brunswick caused a three-hour outage.

On that occasion, line damage forced a switch to a backup system, which didn't work consistently.