Research in Motion (RIM) apologized to users of its popular Blackberry smartphone in the Americas on Wednesday after they were hit by an outage in email service overnight, the second in less than a week for some customers.

RIM said in a statement that the email service interruption late Tuesday appears to have been caused by a flaw in two recently released versions of Blackberry Messenger.

"Message delivery was delayed or intermittent during the service interruption," the Canadian company said, although "phone service and SMS services on BlackBerry smartphones were unaffected."

"RIM has taken corrective action to restore service," the company said. "RIM continues to monitor its systems to maintain normal service levels and apologizes for any inconvenience to customers."

RIM did not say how many Blackberry users were affected by the outage, which came six days after technical problems affected delivery of emails to some users in North America.

RIM blamed the latest disruption on "a flaw in two recently released versions of BlackBerry Messenger (versions and that caused an unanticipated database issue within the BlackBerry infrastructure."

The company encouraged users who downloaded or upgraded BlackBerry Messenger since December 14 to upgrade to the latest version.

RIM's share price shed 1.03 percent to 67.22 dollars in electronic trading ahead of the opening of Wall Street.