Formed as 310th Bombardment Group (Medium) on 28 January 1942. Activated 15 March 1942. Used B-25s to prepare for overseas service. Moved to the Mediterranean Theatre, October-December 1942 and assigned to Twelfth AF. Engaged mainly in support and intervention operations in Tunisia, Sicily, Italy, Corsica, Sardinia and southern France; also flew some missions in Austria and Yugoslavia. Attacking ports and ships to help defeat Axis forces in North Africa, December 1942-May 1943. Bombed airfields, landing fields and gun emplacements on Pantelleria, Lampedusa and Sicily, May-July 1943. Supports the Allied landing at Salerno, September 1943. Assisted the route to Rome, January-June 1944. Supported the invasion of southern France, August 1944. Hit German communication bridges, railway lines, marshalling yards, viaducts, tunnels and road junctions - in Italy, August 1943-April 1945. Also dropped propaganda leaflets behind enemy lines.
Received a UCR for a mission in Italy on 27 August 1943 when, despite persistent attacks by enemy interceptors and anti-aircraft artillery, the group effectively bombed the marshalling yards at Benevento and also destroyed a number of enemy aircraft. Awarded 2nd UCR for another mission in Italy on 10 March 1945 when the group, maintaining a compact formation in the face of severe anti-aircraft fire, bombed the Ora railway bridge, a vital link in the German supply line. Inactivated in Italy on 12 September 1945.