The WikiLeaks website says it's under a forceful Internet-based attack, and the site is inaccessible to users in U.S. and Europe.
The site, which just distributed a trove of U.S. diplomatic documents, said in a Twitter message on Tuesday morning that it's under a "distributed denial of service attack," a method commonly used by hackers to slow down or bring down sites.
The site was under attack Sunday, but Tuesday's attack appears to be more powerful. WikiLeaks said the malicious traffic was coming in at 10 gigabits per second, which would make it a relatively large effort.
The WikiLeaks site is hosted in Sweden and devoted to releasing anonymously submitted documents.