From the Weekly Resume of the Naval Military and Air Situation for the week ending 19th September 1940, as reported to the War Cabinet:
Air Situation : Great Britain.
29. Enemy operations were chiefly confined to London and South-East England, although single attacks were reported in other districts and larger formations bombed Portland and Southampton on the 15th September. Several aerodromes were attacked, but none suffered damage of any importance. The main objectives appear to have been railways, public services and industrial targets : details of damage are set out in the Home Security Section. Attacks were, however, largely indiscriminate, particularly at night. Reports have been received of the occasional use by the enemy of single British aircraft with British markings, and an aircraft that attacked Dover on the 13th September was identified as a Blenheim. A number of parachute mines were dropped in the London area.
53. The enemy’s main attack is still centred on London. The main objectives would appear to have been :— 1. Communications, particularly railways. 2. Electrical undertakings. Another important objective would appear to be the weakening of public morale.
54. The hits on railways in the London Area have not been followed up by attacks on the resulting congestions of traffic in the marshalling yards.
55. The moral effect of the intensification of the A.A. barrage on the public has been very striking.
61. Killed, 988; injured 4,051 (including slight casualties). The figures for London during the period are: killed, 711; injured 1,042. These must be regarded as approximate.
62. This problem remains acute and much of the dislocation of communications is due to unexploded or delayed action bombs. They have also necessitated the temporary evacuation of considerable numbers of people. Every effort is being made to strengthen the bomb disposal parties to deal with the various aspects of the situation.
63. A formidable parachute mine made its first appearance among the enemy’s weapons on the 17th and was again used on the nights of the 17th/18th and the 18th/19th. The mine is in the form of a cylinder about 8 ft. in length by 2 ft. diameter, and its blast force is very extensive. Preliminary inspection supports the view that the mines are the ordinary magnetic ones and already a number have been rendered harmless by Naval personnel.