The controversial file-sharing website The Pirate Bay has experienced a distributed denial of service attack, according to the site's Facebook page.
In a message posted at about 6.30 GMT, The Pirate Bay wrote: "We're under a quite big DDoS attack. We don't know who's behind it but we have our suspicions..."
Two hours later, it said that the DDoS attack was still ongoing.
At the time of writing, thepiratebay.se appeared to still be accessible from the UK.
However, according to TorrentFreak, people around the world were unable to access The Pirate Bay for nearly 24 hours.
TorrentFreak suggested that The Pirate Bay has been attacked for condemning a DDoS hack on Virgin Media's website, which was carried out by a group connected to the Anonymous hactivist group last week.
It was believed that Virgin Media was attacked as a protest against the internet service provider (ISP) blocking users' access to the file-sharing website since 2 May, following a High Court order.
At the time, The Pirate Bay said: "Seems like some random Anonymous groups have run a DDoS campaign against Virgin Media and some other sites.
"We do NOT encourage these actions. We believe in the open and free internets, where anyone can express their views. Even if we strongly disagree with them and even if they hate us.
"So don't fight them using ugly methods. DDoS and blocks are both forms of censorship."