Air Operations, Aleutians

11th Air Force operations against Attu are canceled because of bad weather, but 20 343rd Fighter Group P-40s attack Kiska.

Air Operations, Bismarcks

• 43rd Heavy Bomb Group B-17s and 90th Heavy Bomb Group B-24s attack the Vunakanau airfield at Rabaul.
• During the night, 3rd Light Bomb Group A-20s attack the Gasmata airfield on New Britain and nearby targets.

Air Operations, CBI

• 10th Air Force bombers and fighter-bombers complete their three-day pre-monsoon effort against Japanese lines of communication in western Burma. During the effort, a total of 130 effective combat sorties delivered 340 tons of bombs against rail yards at Prome, oil installations at four locations, and various other targets.

Air Operations, Europe

• 2 Mosquitos bomb a locomotive shed at Tergnier without a loss.

• 3 Mosquitos are sent to Berlin, 23 aircraft lay mines in the southern Biscay, and there are 5 OTU sorties.
• There are no losses.

NASAF B-17s attack Grosseto Airdrome.

Air Operations, Mediterranean

Warhawks destroy 7 giant Me-323s near Decimomannu airfield, Sardinia.

Air Operations, New Guinea

V Bomber Command B-25s attack barges between Madang and Cape Cretin.

Air Operations, Sardinia

• 325th Fighter Group P40s down 6 Axis fighters, plus 7 Me-323 six-engine heavy transports that are caught fleeing Decimomannu Airdrome ahead of an attack by NASAF B-25s.
• While escorting other NASAF B-25s against Villacidro Airdrome, 82nd Fighter Group P-38s down 7 Axis fighters and 1 Ju-88.
• NASAF B-25s also attack Alghero Airdrome.
• P-38s attack Milis Airdrome, various port facilities, and targets of opportunity aroung the island.

Air Operations, Sicily

A 1st Fighter Group P-38 downs an Fi-156 observation plane near Trapani/Milo Airdrome.

Air Operations, Solomons

During the night, XIII Bomber Command B-17s and B-24s mount light harrassing attacks against the airfield at Ballale Airdrome and the Kahili area to mask a mine-sowing operation off Buin by AirSols TBFs.

Aleutians

Fighting continues on Attu in the Clevesy Pass area where the Japanese hold the high ground and have to be prised out of every position. Men trained in desert warfare have to turn themselves into mountaineers to get behind the enemy. After hard fighting the attackers succeed in advancing into the Sarana Valley. Some progress is also made in the northern part of the island.

Supplies Piled on the Beach at Attu, Aleutian Islands, 20 May 1943.

Battle of the Atlantic

• The US 10th Fleet is formed to control US anti-submarine operations in the Atlantic.
• Liberator 'P' of No 120 Squadron sights U-258 on the surface with cannon fire and a single 600lb depth charge. The U-boat is observed down the stern and wallowing in heavy seas then sinking stern first.

U-258

Burma

It is officially announced that the three-month commando operations carried out by the Chindits commanded by Gen Orde Wingate have ended. In their guerilla actions behind the enemy lines the Chindits have lost a lot of their effectives.

China

The Chinese counterattack in the Middle Yangtze front.

Tunis, Tunisia - French soldiers marching in the Allied Victory Parade along Avenue Gambetta. American soldiers standing at parade rest, 20 May 1943.

Victory Parade in Tunis

Pacific

The US submarine Pollack (SS-180) sinks the Japanese armed merchant cruiser Bangkok Maru (5350t) southeast of Jaluit, Marshalls. Pollack is damaged by depth charges by a counterattack by a torpedo boat, but remains on patrol.