"We have arrested four persons today among whom is the main accused Iftikar Alam, who fired during the clash," Joint Commissioner of Police (Crime) Pallab Kanti Ghosh told PTI.
"Arms used in the clash were also recovered from Alam," he added.
Three others arrested along with Alam were Manoj Mali, Kishore Paswan and Shib Raut, he said.
"Late last night, four persons were detained from Singhi Bagan area of Jorasanko for their involvement in the incident. Two of them were released while two others Ashok Shah and Papai Singh were arrested," Ghosh said.
Sub-inspector of Girish Park police station, Jagannath Mondal was injured after he was hit by a bullet during a clash allegedly between two political parties at Singhi Bagan soon after yesterday's voting for Kolkata Municipal Corporation.
Later, West Bengal Chief Minister Mamata Banerjee visited Mondal at the hospital and said his condition was stable.
