'RV-4' was a Soviet combined air and sea operation against the German convoy routes round the extreme north of German-occupied Norway (11/29 May 1944).
On 11 May a German convoy was spotted by a Petlyakov Pe-2 reconnaissance aeroplane off Svaerholt, and a force of six Ilyushin Il-4 torpedo bombers of the 9th Guards Mining and Torpedo Air Regiment, accompanied by five fighters, was ordered to attack it off Makkaur, and another force of five Douglas Boston torpedo bombers, six level bombers and 10 fighters to attack it off the Kongsfjord, sinking V 6113.
On 13/14 May Soviet air units carried out 10 attacks totalling 217 sorties on shipping targets in the area of Kirkenes. The 4,121-ton Pernambuco and 5,898-ton Patagonia were set on fire, UJ 1210 was damaged, and a minesweeper and a patrol boat suffered slight damage. Messerschmitt Bf 109 fighters and Flak shot down at least six of the Soviet aircraft.
On 15 May Soviet attacks sank the 2,928-ton freighter Johann Faulbaums off Kirkenes, and on the following day UJ 1210 off the Varangerfjord.
On 15/16 May the Soviets launched a combined attack on a German eastbound convoy, the attackers including the gunboat K-1 and 10 waves of level and torpedo bombers, the latter with fighter cover, and during these the 3,502-ton freighter Solviken was sunk by a torpedo and the 3,672-ton freighter Herta Engeline Fritzen took a bomb hit in the bow.
The submarines S-15, S-56, S-103 and M-201 were deployed on 16 May. The last twice missed the E.120 convoy off Makkaur, and shortly after this the first also missed the convoy off the Syltefjord before surviving a concentrated depth-charge attack by the submarine chasers UJ 1209, UJ 1212 and UJ 1219.
On 29 May S-103 unsuccessfully attacked UJ 1209, UJ 1211 and UJ 1219 off the Laksfjord.