Bombing of Calcutta
The Bombing of Calcutta were a series of aerial raids carried out by the Imperial [Japanese Army Air Force] on Calcutta, the former capital of British India, during the Second World War. The bombing caused significant damages to infrastructure and killed hundreds, but failed to achieve their primary goal of disrupting Allied supply lines.
Background
After the end of monsoon in 1942, the Imperial Japanese Army Air Force became more active, raiding northeastern Assam. The next targeted Calcutta, the former capital of British India and a significant port on the Bay of Bengal. Their objective was to destroy Calcutta port and delay Allied preparations for a counter-offensive. The 7th Air Brigade had been given the responsibility and they had carried out rehearsals in Malaya in November. In late November 1942 the brigade was reinforced by some aircraft of the Imperial Japanese Navy Air Service and, as reconnaissance showed a large concentration of shipping at Calcutta, the Japanese decided to raid the airfields in the Chittagong area at the end of the month to draw the Allied fighters away from Calcutta which was to be attacked on 5 December, but the attack was delayed till 20 December.Bombing
1942
On 20 December 1942, aircraft of the Imperial Japanese Army Air Force started bombing Calcutta, causing damage to infrastructure and multiple casualties. The bombing campaign continued till 24 December. Airstrikes on Christmas Eve mainly targeted Europeans but failed to cause significant damage or human casualties. The targeted Howrah Bridge wasn't damaged in the raids.Calcutta's air defence systems forced the Japanese pilots to fly high to evade them, bombing raids occurring only in the night. Bombing raids mostly affected the industrial area and displaced 350,000 people. The United States Army Air Force was deployed in Calcutta to engage Japanese aircraft.
1943
The Royal Air Force bomber squadrons responded to these raids by destroying many Japanese aircraft and a Japanese aircraft carrier. By 1943, air defences were strengthened and RADAR guided night fighters were deployed which destroyed several Japanese Mitsubishi Ki-21 and Mitsubishi Ki-46 fighters.In January 1943, multiple Japanese raids were foiled by the Royal Air Force.
In August 1943, the Royal Air Force deployed Spitfires.
On 5 December 1943, Japanese bombing of Calcutta's Kidderpore docks caused hundreds of deaths and destruction of several ships and warehouses. Japanese aircraft dropped heavy explosives and anti-personnel bombs on the docks during the day, not facing any resistance. The docks were devastated. Royal Air Force warplanes were deployed but they failed to engage the Japanese bombers.