BERLIN (AP) – Police raided the premises of leftist groups in cities across Germany Wednesday on suspicion of a plot to attack next month’s G-8 summit.

More than 900 federal and local police officers in cities including Berlin, Hamburg and Bremen searched some 40 apartments or offices used by various leftist groups, federal prosecutors said in a statement.

The prosecutors said they were investigating more than 18 individuals suspected of organizing a terrorist group. They said they were focused on dismantling a Web server where many leftists and groups and projects maintained their internet sites and mailing lists.

“The militant extreme left groups and their members are suspected of having founded a terrorist group, or of being members of such an organization, with the specific goal of staging firebombings and other violent attacks in order to disrupt or prevent the upcoming G-8 summit,” the statement said.

The Anti-Fascist Leftists of Berlin said the searches targeted activists who were organizing protests against the summit of the Group of Eight industrialized nations.

“The only point of these searches is to criminalize and disrupt the protests against the G-8,” the group said. “The accusation that terrorists would coordinate their movements through a leftist-run Internet server is ridiculous.”

Federal investigators have expressed concern the summit in the Baltic Sea resort of Heiligendamm could be a target for attack.

In December, anti-G-8 activists splashed paint on a hotel at the resort in northeastern Germany.

G-8 summits have often been a magnet for protests against globalization. At a summit in Genoa in 2001, the demonstrations turned violent, with protesters and police battling in the streets for days.

German security officials have built a $17 million fence around the resort in an effort to keep protesters from the event, hosted by German Chancellor Merkel. The leaders of America, Russia, Britain, France, Italy, Canada, and Japan are also to attend.