Reichsfuehrer-SS Heinrich Himmler inspects the concentration camp at Auschwitz, Poland (population 10,900). He orders it expanded to hold 30,000 prisoners and a new camp built 4 km away, at the village of Birkenau, for an expected 100,000 Soviet prisoners of war.
Bulgarian Prime Minister Bogdan Filov signs the Tripartite Pact allowing Germany to attack Greece through Bulgaria. In return, Hitler offers Bulgarian Tsar Boris III all the territory lost in WWI to Serbia and Greece.
US Navy forms Support Force, Atlantic Fleet, comprising destroyers and patrol plane squadrons to protect convoys on the American side of the Atlantic Ocean.
Italian garrison (29 Italian officers & NCOs, 273 Libyan soldiers) surrenders El Tag fort and Kufra oasis in Southeastern Libya to Free French troops. Italian casualties are 3 Libyan soldiers killed & 4 wounded, while French have 4 dead & 21 wounded.
Eritrea, East Africa. 2 battalions from 4th Indian Division and 2 Free French battalions (under British Brigadier Rawdon Briggs) reach Mescelit Pass 15 miles Northeast of Keren. “Briggs Force” lacks artillery for a major offensive but will distract the garrison at Keren and cause Italian reserves to remain at port of Massawa instead of reinforcing Keren. As German mining of the Suez Canal keeps British aircraft carrier HMS Formidable at anchor in Port Sudan, she launches 5 Fairey Albacore biplanes to bomb Massawa harbour, but they do little damage. Italian submarines Gauleo Ferraras, Perla and Archimede begin escaping from Massawa. They will go around the Cape of Good Hope, refuel from German vessels and arrive at Bordeaux, France, between May 7-20.
British minesweeping trawler HMT St. Donats sinks in a collision with escort destroyer HMS Cotswold 45 miles East of Grimsby, England.