Can you tell me about Tabarra?

Context: Tabarra agitation of 1939 was an event when some 18,000 Shias were jailed during months of March, April, and May 1939 in Lucknow, India.

A civil disobedience movement was at once started by Shias following the Congress Government communique of 31 March 1939. Sunnis called off their civil disobedience movement but its effect on Shias was far greater than anticipated; they had the authority of two committees and the practice of thirty years in support of their position. Some 1800 Shias courted arrest, including prominent Shia figures such as Syed Ali Zaheer, the Princes of the former royal family of Awadh, Sayed Muhammad Naseer Naseer-ul-Millat the son of Maulana Nasir a respected Shia mujtahid, Maulana Sayed Kalb-e-Husain and his son Maulana Kalb-e-Abid and the brothers of Raja of Salempur and the Raja of Pirpur, important ML leaders. It was believed that Maulana Nasir himself besides the top ranking ML leaders such as Raja of Mahmudabad and Raja of Pirpur would together court arrest. Maulana Azad, appointed an arbitrator by the parties, called a conference of Shias and Sunnis, but it failed to produce a settlement. Azad conveyed to Sir Haig, the Governor, his view that the communique was 'based on inadequate appreciation of the situation and, therefore, an error of judgement'. But, this statement came just a day before the Barawafat, and a Madhe-Sahaba procession was taken out. The Shias too were allowed a counter-procession, it was disturbed and resulted in a serious riot. Several people died and police had to open fire several times. The following year i.e. 1940, the district authorities banned the public recitation of Madhe-Sahaba and Tabarra in processions and meetings held in public places.

Answer: Civil disobedient movement in 1939 is an event that is called Tabarra agitation. Around 18,000 Shias were jailed during 1939 in Lucknow, India