German authorities arrested Wednesday four nationals who are suspected of forming an extremist group to attack mosques and Islamic centers in the country, Al Arabiya reported. The four detainees — three men and a woman — are believed to have been planning attacks on well-known Salafist Muslims in Germany and on housing places for asylum-seekers. The German police said they seized weapons and explosives found in the detainees' home, asserting that they are being held on terrorism charges. In May 30, the police in Frankfurt said they thwarted a plan by alleged Islamic extremists to attack a popular bicycle race on the May Day holiday.