Just after midnight 340 miles North of Bermuda, U-578 sinks Dutch MV Polyphemus (15 Chinese crew members killed). 60 survivors (including 14 survivors from Norwegian tanker MV Norland picked up by Polyphemus on 25 May near Bermuda) in 5 lifeboats are questioned by U-578 and given a heading for New York. On 29 May, 1 lifeboat is provided with water and given further directions by U-566. 2 lifeboats are rescued by a Portugese ship after 1 week. The other 3 lifeboats land at Nantucket Island, Massachusetts.
Libya. Overnight, Rommel attacks with all his tanks around the Southern (desert) end of the Allied defenses. On his left, Italian Ariete Division engages 3rd Indian Motor Brigade (200 killed and wounded, 1000 taken prisoner) at dawn for 3 hours, before moving on to the old Ottoman fort at Bir Hacheim where they are stopped by 1st Free French Brigade under General Marie-Pierre Koenig. The French fire turn-of-the-century 75mm field guns over open sights in anti-tank role and destroy 32 tanks in 45 minutes. In the middle, 15th and 21st Panzer Divisions seek out the main British armour, advancing 25 miles until stopped South of Bir El Harmat at noon by British 1st Armoured Division. Furthest to the East on Rommel's right flank, 90th Light Division reaches El Adem (only 10 miles South of Tobruk) by mid-morning, overrunning several supply bases and 7th Armoured Division’s HQ as well as temporarily capturing Divisional commander General Frank Messervy. Despite these setbacks, General Ritchie’s Southern defenses have held and the German tanks are now trapped between minefields to the West and numerically-superior British armour to the North and East, in an area about 100 square miles that will become known as the Cauldron.
At 3.19 AM 1260 miles Northwest of St. Barts, Leeward Islands, U-172 sinks British tanker MV Athelknight (9 dead; 25 survivors picked up after 28 days by British SS Empire Austin; 18 survivors in a lifeboat land at St. Barts on June 23).
At 10.51 AM 100 miles Southwest of Port Salut, Haiti, U-558 sinks US Army transport ship Jack carrying 59,000 100-pound bags of sugar from Puerto Rico (27 crew, 3 gunners and 7 US Army passengers killed; 16 survivors in a lifeboat picked up by US submarine USS Grunion on May 31; 7 survivors on a raft picked up after 32 days).
At 11.03 AM in the Gulf of Mexico, U-753 sinks Norwegian tanker MV Hamlet (all 36 hands escape in lifeboats which are towed to Morgan City, Louisiana by fishing boats).
Luftwaffe attacks convoy PQ-16 all day. British SS Lowther Castle is sunk by He111 torpedo bombers. Ju-88s sink American SS Alamar & SS Mormacsul, British SS Empire Purcell & British CAM ship Empire Lawrence. Several other ships are damaged including Polish destroyer Garland & American SS City of Joliet, which sinks the following morning.
Battle of Kharkov. Germans continue reducing the Soviet forces trapped in the Izium pocket and snuff out the Eastward breakout, recapturing the town of Lozovenka.
Czechoslovakians Jan Kubiš and Jozef Gabčík (flown from England to Czechoslovakia on December 28 1941 by the British Special Operations Executive) ambush SS-Obergruppenführer Richard Heydrich in the Prague suburb of Libeň, as he drives to meet Hitler in Berlin. Heydrich suffers severe injuries to his diaphragm, spleen and lung from a converted anti-tank mine thrown at the car (and will die of sepsis on June 4).
In the North Sea 43 miles East of Great Yarmouth, British minesweeper HMS Fitzroy hits a British mine and sinks (12 killed). A German Ju87 Stuka dive bomber sinks British anti-submarine trawler HMT Arctic Pioneer off Portsmouth Harbour, England (18 killed, 16 survivors).
At 2.20 PM, US aircraft carrier USS Yorktown arrives at Pearl Harbor, Hawaii, for repairs following the Battle of the Coral Sea on May 8 (repair estimates range between 2 weeks and 3 months). Admiral Frank Fletcher is surprised to learn that his Task Force 17 (with USS Yorktown) will leave for Midway Atoll in 2 days. Yorktown’s crew is dismayed not to get time to recover Stateside but repair work stats immediately.
5000 Japanese troops aboard 12 transports, escorted by cruiser Jintsu and 10 destroyers (commanded by Rear Admiral Raizo Tanaka), leave Saipan and Guam for the invasion of Midway Atoll. Japanese First Carrier Striking (4 aircraft carriers Akagi, Hiryū, Kaga and Sōryū, battleship Kirishima, cruisers Mikuma, Chikuma, Tone and Haruna and 12 other vessels under the command of Vice Admiral Chuichi Nagumo) leaves Japan in support of the invasion.
Japanese submarine I-25 launches its floatplane to reconnoiter US Navy's Naval Air Station Kodiak, on Kodiak Island near the mainland of Alaska, and spots a US cruiser and 2 destroyers. The intelligence is so important to their planned attack on the Aleutian Islands that another submarine I-26 lurks nearby to recover the floatplane, in case I-25 cannot. Japanese submarine I-19 dives while preparing to launch its floatplane off Bogoslof Island, in the Aleutian Islands, when lookouts think they spot a US destroyer (the aircraft is destroyed).