Facebook said on Monday it is blocking a website called "Web 2.0 Suicide Machine" that helps users delete their social network profiles.

The number one social network also said it had sent a "cease-and-desist" letter to another website, Seppukoo.com, which also helps you kill off your virtual identity.

The Web 2.0 Suicide Machine site, which features a hangman's noose on its homepage, deletes profiles, friends and other information on Facebook, MySpace, Twitter and LinkedIn for users who provide their account information.

"This machine lets you delete all your energy sucking social-networking profiles, kill your fake virtual friends, and completely do away with your Web2.0 alter ego," it says.

Facebook, in a statement to AFP, said the suicide site was in violation of Facebook rules.