Militants and hate groups increasingly use social networking sites such as Facebook, MySpace and YouTube as propaganda tools to recruit new members, according to a report by the Simon Wiesenthal Center.

The report released on Wednesday noted a 25 percent rise in the past year in the number of "problematic" social networking groups on the Internet.

The report was based on "over 10,000 problematic web sites, social networking groups, portals, blogs, chat rooms, videos and hate games on the Internet which promote racial violence, anti-semitism, homophobia, hate music and terrorism."

"Every aspect of the Internet is being used by extremists of every ilk to repackage old hatred, demean the 'Enemy,' to raise funds and since 9/11, recruit and train Jihadist terrorists," the Simon Wiesenthal Center said in a statement.

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The Jewish human rights group named after the renowned Nazi hunter has been monitoring the use of the Internet by extremists for over a decade.

It said the rise of social networking sites such as Facebook had accelerated the spread of racist and bigoted views in recent years.

It said Facebook officials had met with its experts and pledged to remove sites that violate its terms of usage, "but with over 200 million users, online bigots have to date outpaced efforts to remove them."

It noted that Facebook recently removed several Holocaust denial sites, and it released a statement from the Palo Alto, California, company noting that the site is also widely used to advance positive agendas.

"Where hateful content is uploaded and reported, Facebook removes it and disables the responsible accounts," the Facebook statement said.

Extremist groups are also setting up their own social networking sites, the report said, picking out one called "New Saxon," described as "a Social Networking site for people of European descent" produced by an American Neo-Nazi group called the National Socialist Movement.

Other groups have created online games such as "Special Operation 85 - Hostage Rescue," a game created by an Iranian organization in which the player has to locate nuclear scientists taken hostage by Americans in Iraq and believed to be held in an Israeli prison.

The most often targeted groups on the Internet according to the report include Jews, Catholics, Muslims, Hindus, gays, women and immigrants.