The Jallianwala Bagh massacre, also known as the Amritsar massacre, took place on 13 April 1919. A large, peaceful crowd had gathered at the Jallianwala Bagh in Amritsar, Punjab, British India, to protest against the Rowlatt Act and the arrest of pro-independence activists Saifuddin Kitchlu and Satyapal. In response to the public gathering, the temporary brigadier general R. E. H. Dyer, surrounded the people with his Gurkha, Baloch and the 59th Scinde Rifles of the British Indian Army. The Jallianwala Bagh could only be exited on one side, as its other three sides were enclosed by buildings. After blocking the exit with his troops, he ordered them to shoot at the crowd, continuing to fire even as the protestors tried to flee. The troops kept on firing until their ammunition was exhausted.Estimates of those killed vary from 379 to 1,500 or more people and over 1,200 other people were injured of whom 192 were seriously injured. Britain has never formally apologised for the massacre but expressed "deep regret" in 2019.
The massacre caused a re-evaluation by the British Army of its military role against civilians to "minimal force whenever possible", although later British actions during the Mau Mau rebellion in the Kenya Colony have led historian Huw Bennett to comment that the new policy could sometimes be put aside.The army was retrained and developed less violent tactics for crowd control. The level of casual brutality, and lack of any accountability, stunned the entire nation, resulting in a wrenching loss of faith of the general Indian public in the intentions of the United Kingdom. The attack was condemned by the Secretary of State for War, Winston Churchill, as "unutterably monstrous", and in the UK House of Commons debate on 8 July 1920 Members of Parliament voted 247 to 37 against Dyer. The ineffective inquiry, together with the initial accolades for Dyer, fuelled great widespread anger against the British among the Indian populace, leading to the non-cooperation movement of 1920–22.Some historians consider the episode a decisive step towards the end of British rule in India.