BERLIN (AFP) - Germanys interior minister, Thomas de Maiziere, warned Monday against blanket suspicion of Muslims in the wake of fresh terror warnings in the country. Speaking at the annual congress of the GdP police union, the minister said the government would not stand by idly if the fear of an attack were used to whip up hatred of Muslims living in Germany. We must not abuse the current debate to create general suspicion against law-abiding Muslims, De Maiziere said. He said terrorists aimed to spread fear and horror and warned against allowing the threat of an attack to spark hysteria. We wont do them that favour, he said. He also launched a broadside against self-appointed terrorism experts speculating about the threat, saying he wished they would keep their views to themselves. Last week German authorities beefed up security at crowded places such as airports and train stations after De Maiziere said that Berlin had received a tip-off from a foreign partner about an attack planned this month. The cupola on Germanys Reichstag parliament building was closed until further notice to visitors Monday after media reports said the popular tourist site was a potential target for Islamist extremists. No reason was given for the move and pre-arranged group visits were still allowed. A debate about Islam in German society has raged for months after a central banker argued in what has become a best-selling book that Muslim immigrants were endangering the German way of life by refusing to integrate. Chancellor Angela Merkel has declared multiculturalism in Germany to be a failure and called on Germans and newcomers alike to do more to foster integration.