Netflix, Instagram, Pinterest and other sites hosted on Amazon servers were unavailable after power outages.

Severe thunderstorms in the eastern US have caused widespread power outages and affected a number of popular websites hosted by online seller Amazon.

The Washington Post’s website reported that the storms knocked out power for “more than 1.5 million homes and businesses” across Maryland and Virginia on Friday night.

Technology site VentureBeat reported that websites using Amazon’s Elastic Compute Cloud service in North Virginia like Netflix, Instagram, Pinterest, Heroku were all down at one point late Friday evening and early Saturday morning.

Checks by Al Jazeera at 07:00 GMT on Saturday showed that most of these sites, excluding Instagram, were working properly.

Instagram, the popular photo sharing site that Facebook recently bought for $1bn, posted a message on Twitter from its support account at 03:16 GMT, “We’re currently experiencing technical difficulties and we’re working to correct the issues. Thanks for your patience.”

At 03:50 GMT, NetFlix, a popular site for streaming movies and TV programmes, also posted a message on Twitter from its support account, “We’re aware that some members are experiencing issues streaming movies and TV shows. We’re working to resolve the problem.”

At 03:40 GMT, Amazon posted an update on its Web Services site on its Elastic Compute Cloud server: “We can confirm that a large number of instances in a single Availability Zone have lost power due to electrical storms in the area. We are actively working to restore power.

The last message, posted at 05:36 GMT, said,”We continue to bring impacted instances and volumes back online. As a result of the power outage, some EBS volumes may have inconsistent data.”

Sean Ludwig, from VentureBeat, wrote in a blog post, “The outage underscores the vulnerabilities of depending on the public cloud versus using your own data centers.”

The outages on Amazon’s cloud server come two weeks after a similar incident when a number of popular websites hosted by Amazon went down. A report into the incident by Amazon found that a configuration error was made during a routine upgrade.

“With the critical Amazon outage, which is the second this month, we wouldn’t be surprised if these popular services started looking at other options,” Ludwig wrote.