Which incident forced Gandhiji to withdraw the Non-cooperation Movement?

The Chauri Chaura incident that took place on 5 February 1922 was the main reason which forced Gandhiji to withdraw the Non-cooperation movement. During the period of Non-cooperation movement, a clash took place at Chauri Chaura which is a small town in the district of Gorakhpur, Uttar Pradesh. The incident happened after the police officers had attacked a few volunteers while picketing a liquor shop and arrested their leader. The whole crowd who had gathered in that location went to the police station and trashed the entire premises and shouted slogans against the government. This led to a clash between people and policemen and some violent mob in the crowd sets fire to the police station with 22 policemen inside, killing all of them trapped inside burned to death.

Gandhiji felt that the revolt was veering off-course and was disappointed that the revolt had lost its non-violent nature. He did not want the Non-cooperation movement to fall into a contest of violence between policemen and angry mobs attacking each other victimizing civilians in between. Gandhiji took upon himself the responsibility of the bloodshed and made an urgent appeal to the public and called off the campaign. He went on fasting that lasts for 3 weeks and called off the non-cooperation movement completely. British government however arrested Gandhiji and several leaders for leading the Non-cooperation movement mentioning that it led its way for this Chauri Chaura incident.