II "Gruppe" also trained for long-range operations under the command of IV "Fliegerkorps". It was brought up to strength with 35 H-16s at Deblin: where it remained based until 10 May 1944. It trained from January to March 1944. From 31 March to 7 April 1944, it dropped supplies to the Kovel pocket, and rendered support to the 5th SS Panzer Division Wiking. It flew rail interdiction; bombing yards at Rovno, Kiev and Shepetovka from 4–11 May. It joined I "Gruppe" at Focsani in Romania to evacuate the Crimea, from 11 to 16 May 1944. It moved back to Deblin but the fuel crisis now prevalent in the "Luftwaffe", slowed down the pace of operations. On 21/22 June, with I. and III. "Gruppen", it bombed Poltava Air Base, which housed United States Army Air Force bombers that had been flying shuttle-missions to Eastern Europe and landing in the Soviet Union. The raid caused significant losses to the US Fifteenth Air Force. A Heinkel He 177 from 2./"Aufklärungsgruppe" 100 shadowed the 3rd Bombardment Division, 45th Bombardment Wing to Poltava. The raid, carried out by KG 55, KG 53, KG 27 and KG 4, destroyed 43 B-17 Flying Fortress' damaged 26, and destroyed 200,000 US gallons of aviation fuel.