Section 51A(1)(a) in The Madras City Police Act, 1888
(a)Central Act XLV of 1860-- that the movements or acts of any person in the City of Madras are causing or are calculated to cause, alarm, danger or harm to person or property, or that there are reasonable grounds for believing that such person is engaged or is about to be engaged in the commission of any offence involving force of violence or punishable under Chapter XII, XVI or XVII of the Indian Penal Code or in the abetment of any such offence ; and