A major service outage afflicted users of the popular BlackBerry smart phones across the United States and Canada on Monday.

Officials with AT&T Inc. and Verizon Wireless said BlackBerry maker Research in Motion Ltd. told them customers of all wireless carriers were affected.

It was not immediately clear how many of the 12 million worldwide BlackBerry subscribers had problems, as some users reported being able to access their service normally Monday afternoon.

But Liberal MP Garth Turner said during a caucus meeting that the incident — the second widespread disruption in 10 months — was having a big impact.

"Everyone's in crisis because they're all picking away at their BlackBerrys and nothing's happening," Turner said. "It's almost like cutting the phone cables or a total collapse in telegraph lines a century ago. It just isolates people in a way that's quite phenomenal."

Bell Canada spokesman Jason Laszlo said the majority of its BlackBerry customers were affected.

The BlackBerry service, which lets users check e-mail and access other data services on their handheld devices, has become a lifeline for many business executives and is increasingly popular among consumers with models like the BlackBerry Pearl.

In a statement, RIM said a "data service interruption" resulted in "intermittent service delays for BlackBerry subscribers in North America." The company said voice and text-messaging services were not affected.

RIM later said data service was restored around 6:30 p.m. ET, about three hours after the outage began.

"No messages were lost and message queues began to be cleared after normal service levels were restored," the company said, apologizing to customers for the inconvenience.

RIM says little

There was no word on what caused the outage.

Major disruptions have been rare but often provoke an angry backlash against Waterloo, Ont.-based RIM because of its typically lengthy silences about the cause and because it eventually gives only cryptic, jargon-laden explanations.

When BlackBerry service suffered a major outage last April, the company remained silent about the cause for two days.

After that outage, BlackBerry co-chief executive Jim Balsillie said that RIM, which has grown to be one of Canada's most valuable companies on the strength of the BlackBerry, said he thought it was appropriate to attack the network failure first and provide more details later.