Germany's third busiest airport has been closed down most of the day after numerous bomb warnings. Several telephone calls were apparently made this morning warning of explosives somewhere around the airport and security officials are taking the calls very seriously. Hundreds of police officers using sniffer dogs are searching all three of the airport's terminals. Incoming planes have been diverted to Cologne airport. Düsseldorf airport deals mainly in charter flights. Around 64,000 people were expected to fly in or out of Düsseldorf airport today. Many families are heading back from their holidays as schools re-open tomorrow after the long summer break. **PHOTO CAPTION*** A man leaving the terminal pushes an old man on a trolly with luggage at the terminal at the Dusseldorf International airport, Germay's third busiest airport, in the German city of Dusseldorf on Sunday, Sept. 14, 2003. (AP Photo/Michael Sohn)