Germany is increasing security at airports and railway stations in light of concrete indications of terrorist attacks being planned for the end of November. Interior Minister Thomas de Maiziere said it followed a tip-off from another, unnamed country. He said Germany had information on sustained efforts by Islamist extremists to carry out attacks. He said the extra security will remain in place until further notice. He told a news conference in Berlin there are grounds for concern, but not for hysteria. He said Germany received a tip-off after two parcel bombs were intercepted en route from Yemen to the United States. One of the bombs was despatched via the German city of Cologne but was only intercepted in the UK.