Adriatic: Pola bombed by 148 Caproni bombers and 11 flying boats; Austrians bomb Venice (September 7) which has balloon barrage defence. Gales abort RNAS attempt to attack Cattaro naval base with 6 Short torpedo seaplanes.
Britain: Three consecutive moonlight raids by Gotha bombers on southeast England (London on September 4) begin 19 night raids (until May 20, 1918). Total casualties 326 including 130 naval recruits killed and 88 wounded at Chatham drill hall. First operational trials of Sopwith Camel night fighters by No 44 Squdronn, commander 22-year-old Captain Murlis Green (4 1/2 Salonika victories 1916-17); 3 on nights September 2-3, 3-4 and 4-5.
Belgium: RNAS drops 18t bombs on Bruges docks (until September 5).
Western Front: Germans bomb St Omer (night September 3-4).
North Sea: Royal Navy Air Service bomb Bruges docks (3 killed), Zeebrugge mole and shipping off Ostend (September 15).
Arctic: U-28 destroyed in explosion of British munitions ship Olive Branch torpedoed off North Cape.
Germany: OHL found and fund Tirpitz’s new Fatherland Party (he addresses first meeting in Berlin September 25; 1.25 million members by July 1918).