The BlackBerry wireless email service from Research In Motion (RIM) appears to have suffered a widespread outage starting Tuesday evening in the US.

Customers on the BlackBerry Forums discussion board complained of having no service starting at about 5:15 p.m. Pacific Time on Tuesday.

Callers to the BlackBerry US technical support line were still greeted with a standard service interruption message early Wednesday morning, saying it "will provide updates as soon as they become available".

New York television news channel NewsChannel4 reported Tuesday night that the problem affected "all users in the Western hemisphere."

However, comments from operators in Asia and Europe, as well as postings to the BlackBerry Forums, suggested that the problem may be limited to North America.

"Officials with RIM said they are trying to reset the system and told NewsChannel4 that they are concerned that the backlog of data, which will rush through when it comes back on line, could cause a bigger problem," the news channel reported on its website.

RIM officials advised people who use BlackBerry as a major way of communications to make backup plans, the channel reported.

A RIM official contacted in France was unaware of the problems, and said she had received messages sent to her BlackBerry as normal. Other RIM officials did not return calls seeking comment.

The outage may have been cause by one of RIM's Network Operating Centres (NOC) going down, according to Emma Mohr-McClune, principal analyst with Current Analysis. "This has happened before," she said. RIM operates two NOCs, both located in Canada, according to Mohr-McClune. The company has considered locating additional NOCs outside of Canada, she said.

Companies that provide BlackBerry service connect their mail servers to a BlackBerry Enterprise Solution (BES) server located on their premises, which in turn is linked to one of RIM's NOCs, according to Mohr-McClune. "All data slides to Canada and back," she said.

RIM may have been fortunate that the outage began at about 5 p.m. Pacific Time, because it would have been after the busiest part of the US working day. Engineers were likely scrambling through the night to bring the service back online before the start of work in the US on Wednesday and in time for customers of Asia and Europe who were also reportedly affected.

The problems come at a time of continued rapid growth for the company, based in Waterloo, Ontario. It added 1.02 million subscribers in the quarter ended 3 March, for a total of approximately 8 million BlackBerry subscribers worldwide. Revenue for the quarter was $930.4 million (£436.95m), up 66% from a year earlier. Net income for the quarter before adjustments was $187.m, the company said.

Peter Sayer, James Niccolai, Dan Nystedt and Martyn Williams contributed to this report.