As the Rowlatt act was hurriedly passed by the imperial Legislative Council, Mahatma Gandhi wanted non-violent civil disobedience against the unjust laws, which would start with a hartal on 6 April. On 10 April, the police in Amritsar fired upon a peaceful processions. As Martial law was imposed and General Dyer took command. On 13 April the infamous Jallianwalla Bagh incident took place. Hundreds were killed and injured. His object, as he declared later, was to ‘produce a moral effect’, to create in the minds of satyagrahis a felling of terror and awe.

On April 13, the traditional festival of Baisakhi, thousands of Sikhs, Muslims and Hindus gathered in the Jallianwalla Bagh (garden) near the Harmandir Sahib in Amritsar. An hour after the meeting began as scheduled at 4:30 pm, General Dyer--without warning the crowd to disperse--blocked the main exits. He explained later that this act "was not to disperse the meeting but to punish the Indians for disobedience." Dyer ordered his troops to begin shooting toward the densest sections of the crowd (including women and children). Firing continued for approximately ten minutes. Many people died in stampedes at the narrow gates or by jumping into the solitary well on the compound to escape the shooting. A plaque in the monument at the site, set up after independence, says that 120 bodies were pulled out of the well. The wounded could not be moved from where they had fallen, as a curfew was declared; and many more died during the night.

As the news of Jallianwalla Bagh spread, crowds took to the streets in many north Indian towns. There were strikes, clashes with the police and attacks on government buildings. The government responded with brutal repression, seeking to humiliate and terrorise people: satyagrahis were forced to rub their noses on the ground, crawl on the streets, and do salaam (salute) to all sahibs; people were flogged an villages (around Gujranwala in Punjab) were bombed. Seeing violence spread, Mahatma Gandhi called off the movement.