London: The BBC's entire network of websites and its iPlayer streaming service crashed on Thursday after a large web attack by hackers.
Thousands of users complained on social media after being met an error message, saying there had been an "internal error" on one of the world's busiest news websites.
It later emerged the corporation had suffered a DDoS a distributed denial of service attack.
BBC technology correspondent Rory Cellan-Jones tweeted: "BBC suffered a DdOS a distributed denial of service attack.
But services are now being restored."
A DdoS attack is an attempt to make an online service unavailable by overwhelming it with traffic from multiple sources.
The BBC press office also issued its statement on Twitter: "We're aware of a technical issue affecting the BBC website and are working to fix this now. We'll update you as soon as we can."
The BBC's main website is the 89th biggest in the world, according to web analytics firm Alexa, and is the seventh-ranked site in the UK.
It is now back online and the corporation is now investigating the cause of the outage.