Facebook on Wednesday suffered its biggest global outage ever as its key applications including Instagram and Messenger went down for more than 8 hours. Facebook and other applications resumed early morning for some users.Facebook hasn’t disclosed what caused the outage yet.

The company, however, did clarify that the service interruption wasn’t due to targeted cyber attack.“We’re focused on working to resolve the issue as soon as possible, but can confirm that the issue is not related to a DDoS attack,” the company said in a tweet.

DDoS, also known as distributed denial-of-service, attack is when multiple devices flood the bandwidth of a targeted system, ultimately causing it to crash.

According to downdetector, the outage began around 9:30PM IST. The live map shows users in India, US and Europe were severely impacted by the outage. Instagram, Messenger and WhatsApp was also down for some users during this period.

The outage map suggests services resumed early morning.

As both the social networking platforms went down, users flocked to Twitter to express their frustration. Some users said that while they could access the mobile apps but could not use key functions such as setting a new status or sharing.

Some were also unable to log into their accounts.The Facebook outage comes shortly after Google users faced similar outage with its Maps and Drive services. Google later apologized for the interruption in the services.

This is not the first time Facebook has experienced such global outage. In November last year, Facebook was down for approximately 40 minutes.

The social networking company had then blamed a test for the interruption in services. The Wednesday outage, however, is the biggest Facebook suffered ever.