on 2 april 1993, nato troops from great britain, france, the netherlands, spain, turkey, germany, and italy as well as the united states launched operation deny flight, a no-fly zone for serbian aircraft over bosnia-herzegovina. it enforced a march 1993 un security council resolution passed to help prevent the war from spreading. the operation also provided close air support to un protection force ground troops serving as peacekeepers, and airstrikes against serb weapons threatening un-designated safe areas in bosnia. the first ang fighter unit involved was the connecticut air national guard's a-10-equipped 103d fighter group. aircraft and personnel from the maryland air national guard's 175th fighter group and michigan air national guard's 110th fighter group joined the contingent from connecticut. along with unit personnel, the six air national guard and six air force reserve a-10s returned to their home stations in mid-january 1994 after flying 520 sorties and accumulating over 1,400 hours of deny flight flying time. air national guard tanker support of deny flight began in june 1994 with the dispatch of 10 kc-135s and 18 aircrews from six units to istres air base, france, and pisa airport, italy. by the time deny flight ended on 20 december 1995, elements of seven air guard fighter and 11 air refueling units had participated in it.