Two men and two women were arrested on Friday in connection with an attack on a police officer during a clash between supporters and opponents of the Citizenship (Amendment) Act in Jodhpur Park on Thursday.

An officer of Lake police station was severely injured in the arm when he came between the warring groups — one supporting the Trinamul and the other the BJP — and was attacked with a blade.

The arrested have been identified as Balaram Singh, Kiran Singh, Kabita Sardar and Sushmita Haldar — all suspected BJP supporters.

They have been booked for murder attempt, causing grievous hurt using dangerous weapons, stopping a public servant from doing his duty and criminal conspiracy, an officer of the police station said.

“Investigations are on,” Debasmita Das, deputy commissioner (southeast division), said.

On Thursday night, a clash broke out between supporters of both parties. A motorcycle was set on fire, which spread to an adjoining tree as the vehicle’s fuel tank burst. A group of men and women attacked a police team, injuring a sub-inspector of the police station.

Trinamul and BJP supporters have lodged complaints blaming each other for the violence.

The police started a suo motu case, based on which some of the accused were identified and arrested early on Friday.

“We were marching peacefully when some TMC people attacked us,” a BJP supporter said.

Trinamul supporters alleged BJP supporters had passed lewd remarks against some women in the Trinamul party office, which led to an argument.