Police officers patrol at the Trocadero Esplanade (also named Human rights Esplanade) in front of the Eiffel Tower in Paris on November 19, 2013 as a manhunt is under way in Paris for a lone gunman who shot and critically wounded a newspaper photographer in his office on November 18 before opening fire outside a bank headquarters and hijacking a car. Officers on foot and in squad cars fanned across the nervous city, taking up positions outside media offices, along the Champs-Elysees avenue and at entrances to underground train stations. Investigators have so far been unable to identify the gunman, described by French Interior Minister Manuel Valls as 'a real danger'.