Luftwaffe Squadron at Rennes France 1940

My wife's uncle (Armourer - 4 Base Ammunition Depot) RAF was killed in the infamous bombing raid at Rennes Railway yards on the 17th June 1940 while evacuating to the Channel Ports. The bombing raid was carried out by the Luftwaffe to hit troop trains. As well as troop trains, civilian trains carrying refugees were also destroyed. Over 800 died in the wreckage and ensuing fires. Could anybody help with what Luftwaffe Squadron was involved and the officers and crew of the aircraft on that bombing air raid? And also the aircraft used ?
Thanks.
David.