Dolomites: Italian mine exploded (night April 17-18), kills 100 Austro-Hungarians and 160 PoWs made as Colonel di Lana taken, but later assaults on Mt Sief fail with loss of 2,000 Italian soldiers.
Mesopotamia – Battle of Bait Aisa (until April 18): 3rd Indian Division (8,362 infantery) storms salient in Turk defences, Gurkhas take 2 guns but 10,000 Turks including German officers (4,000 casualties) counterattack five times to regain salient (British losses 1,600 + 15 MGs).
Verdun: Germans repulsed between Meuse and Douaumont.
Eastern Atlantic: First UE minelayer U73 lays 12 mines off Lisbon (Norwegian steamer sunk).
Italy: Government prohibits trading with Germany.
USA: Meat packers agree to British supervision of meat exports to European neutrals for duration.
Britain: London rumors of Prime Ministers resignation.
Ireland: General Stafford letter from Cork gives Dublin GOC (General Officer Commanding) only waning of Rising (unheeded).