Millions of BlackBerry users in Africa, Europe and the Middle East have been unable to use their BlackBerry messaging services (BBM) and email since midday on Monday.
Some users have also reported difficulty accessing the internet.
The problem has affected consumers from across Bahrain, England, Egypt, Abu Dhabi and South Africa.
According to several media reports, the fault lies in a server in Slough, United Kingdom.
BlackBerry maker Research In Motion issued a statement on Monday afternoon, hours after the problem surfaced but it said very little.
“We are working to resolve an issue currently impacting some BlackBerry subscribers in Europe, Middle East and Africa. We’re investigating, and we apologise to our customers for any inconvenience caused whilst this is resolved.”
Vodacom’s CEO Pieter Uys, who used Twitter repeatedly to communicate issues affecting Vodacom users, tweeted the news to his followers: “RIM has confirmed they are experiencing problems across multiple countries and networks, if you using BlackBerry.”
Canadian-based RIM has lost significant market share to smart phone rivals Google and Apple and retrenched more than 2000 staff in July this year.