The popular BlackBerry mobile device experienced disruptions in service in North America on Monday, but the severity of the outages was unclear, AT&T reported.

The problems stemmed from the BlackBerry data service provided by Research In Motion, maker of the smartphone that's popular among businesspeople. BlackBerry users contacted by InformationWeek reported problems sending and receiving e-mail and other documents. Phone service was not interrupted.

AT&T learned of the outages at 3:30 p.m. Eastern standard time, a company spokesman told InformationWeek. The carrier did not know the extent of the outage, which affected e-mail and other data services, or when the problem would be fixed. "I've got a BlackBerry, and I'm not happy," he said.

BlackBerry data services are provided by RIM over multiple wireless carriers, not just AT&T. "It's not an issue with AT&T or the wireless networks," the spokesman said.

Reuters news agency on Monday reported that RIM sent an emergency notification by e-mail, saying the BlackBerry e-mail service had experienced a "critical severity outage." The e-mail referred to the problem as the "current BlackBerry infrastructure outage."

RIM officials were not immediately available for comment.

The outage is the second widespread service problem reported by RIM in less than a year. In April, a breakdown centered at the company's primary Network Operating Center for North America left 8 million subscribers unable to send or receive e-mails. The center is located at RIM headquarters in Waterloo, Ontario.

The failure at the time raised questions as to whether RIM, which has chosen to keep its entire network infrastructure in-house and in relatively centralized form, can continue to scale to meet demand for BlackBerry services.

Lately, RIM has been pushing the BlackBerry beyond businesses and into the consumer market. Rather than only supporting features for business, BlackBerry devices are available today with multimedia functions, such as music and video players, cameras, and social-networking software.

More than a third of RIM's subscribers are now classified as noncorporate or nongovernment. As of the end of quarter ended Dec. 1, RIM had 12 million users.