Iraq. At 5 AM during Muslim morning prayers, 33 aircraft from RAF Habbaniya and 8 Wellington bombers from RAF Shaibah bomb and strafe Iraqi artillery on the plateau above Habbaniya, causing the Grand Mufti in Baghdad to declare jihad against Britain. Iraqis reply by shelling RAF Habbaniya (13 killed & 29 wounded, including civilians on the base). RAF also bombs Iraqi air force base at Rashid airfield near Baghdad (destroying 22 aircraft on the ground). RAF loses 5 aircraft in all.
Libya. Fighting continues in the German salient at Tobruk. German infantry are held by Allied reserves sent to plug the gap while sandstorms prevent Rommel from using his Panzers. British gunboat HMS Ladybird bombards Afrika Korps positions at Derna.
British destroyer HMS Jersey hits a mine off Grand Harbour, Malta, and sinks next to the breakwater (35 crew killed, 48 wounded). As a result, cruiser HMS Gloucester and destroyers HMS Kipling & Kashmir divert to Gibraltar. British steamer Parracombe, carrying 21 crated Hurricane fighters to Malta, sinks on a mine off Cape Bon, Tunisia.
German anti-submarine trawler Vp 808 is sunk by RAF bombing off the island of Borkum, near the Dutch/German border.
British minesweeping trawler HMT Alberic and destroyer HMS St. Albans collide in Pentland Firth between the North of Scotland and the Orkney Islands. HMT Alberic sinks with the loss of 13 crew. The destroyer sails to Southampton for repairs to her bows (completed on June 4). Royal Navy commissions convoy escort ship HMS Lulworth (ex-US Coast Guard Cutter) at New York with a crew from British battleship HMS Resolution (under repair in USA).
Luftwaffe bombs Liverpool again overnight.