A glance at some sporting events and teams that have been affected by attacks and threats:

Munich Olympic Games massacre

Sept 5-6, 1972

A Palestinian terrorist group, going by the name of "Black September," took the Israeli Olympic team hostage and eventually killed 11 athletes at the Munich 1972 Olympic Games. A freeing action of the German police forces on the Fuerstenfeldbruck airport near Munich had failed overnight on Sept 6, 1972, leaving all hostages, five of the Palestinian kidnappers and a German policeman dead.

A Palestinian terrorist wearing a balaclava looks over the balcony of the Israeli team quarters at Building 31 of the Munich Olympic Village, in this Sept 5, 1972 file photo. [Photo/Xinhua]