Microsoft’s online services  - reportedly including Hotmail, Office 365 and SkyDrive - experienced an outage for around three and a half hours overnight.

While Microsoft declined to confirm exactly which services were affected, the BBC said that the company’s email service Hotmail, cloud-based software Office 365 and online document storage and file-sharing service SkyDrive, were among the services that went offline.

The IT giant said that it became aware of a Domain Name Service (DNS) issue causing “service degradation for multiple services” at approximately 8pm PDT (3am GMT).

“We began seeing service restoration at approximately 10.30pm PDT and achieved full service restoration at approximately 11.30pm PDT (6.30am GMT). We are conducting a review of the incident,” Microsoft said in a statement.

The incident brings the reliability of cloud computing services into question, especially as Google’s cloud offering, Google Docs, also suffered an outage for nearly an hour on Wednesday (7 September).

Microsoft’s Office 365 and SkyDrive were hit by outages in August, with some customers saying they lost access to email and other services for up to four hours. The company blamed the problems on a networking issue.