By Karin Matussek

May 9 (Bloomberg) - German federal and state police forces raided 40 sites today as part of investigations into members of a militant group that planned to attack the G-8 summit in Heiligendamm, Germany, next month.

Police and prosecutors conducted searches in Berlin, Hamburg, Bremen and various places in the states of Brandenburg, Schleswig-Holstein and Lower Saxony, the office of the Federal Chief Prosecutor said in an e-mailed statement today.

``The suspects in this probe allegedly belong to a group which is planning to obstruct the G-8 summit with violent actions and bomb attacks,’’ the prosecutor’s office said in the statement.

The G-8 is an international forum for the governments of Canada, France, Germany, Italy, Japan, Russia, the U.K. and the U.S. Other countries that will join the talks include China, Brazil, India, Mexico and South Africa.

Prosecutors are investigating 18 people who may have formed a terrorist group, the office said. In the last two years, the suspects, whose names weren’t disclosed, were involved in 12 bombings against business leaders, government officials and companies in the Hamburg and Berlin areas, prosecutors said.

A second probe concerns three suspects who may have attacked business and government institutions to ``overthrow the current form of state and society in order to establish a communist rule,’’ the office said.

On March 16, a group linked to the suspects in the second probe may have attacked a foreign chamber of commerce and a foreign industry association in Berlin, prosecutors said.

To contact the reporter on this story: Karin Matussek in Berlin at kmatussek@bloomberg.net