German police have searched the homes of four alleged Chinese spies in Munich, federal prosecutors said Tuesday, according to dpa. A spokesman in Karlsruhe confirmed the quartet were under investigation for espionage. Germany"s Foreign Ministry said it was in contact with the federal prosecutions office, but it had no comment to make about the investigation. Munich has the world"s largest exile community of Uighur people, a mainly Muslim minority which resents Han Chinese settlement in their homeland in western China. The spokesman said none of the four suspects had been formally placed under arrest. The federal prosecutor"s office is in charge of inquiries into espionage and subversion. Spiegel Online, a news website, said police swooped Tuesday. The Chinese were believed to have infiltrated the Uighur community and were alleged to have passed reports on to one of the Chinese consuls in Munich. A consul is immune from arrest or interrogation, but the four suspects did not enjoy immunity, Spiegel said. German investigators had observed the consul in secret meetings with the four. The spying allegations have caused tension between Germany and China, according to Spiegel Online. The German Foreign Ministry rejected that. "Our relations with China and are good and will not be harmed by this matter," a spokesman said. Spiegel Online added that a Chinese official at the Munich consulate had voluntarily gone home two years ago after Germany complained that he had been observed meeting alleged informers a dozen times. Beijing claims the Uighur exile movement, the Uighur World Congress, is a terrorist grouping.