Four people were arrested after a clash between Trinamool Congress and CPI-M activists in West Bengal's North 24 Parganas district, police said on Tuesday.
The clash that took place on Monday night in Belgharia left three Marxist workers injured, police said.
"Two CPI-M and two Trinamool members have been arrested and an inquiry over the incident is on," police said. The four arrested were later produced in court.
Left-backed CITU leader Subhas Mukherjee and former member of the legislative assembly Manas Mukherjee were among the injured.
CPI-M leader Nepal Deb Bhattacharya alleged that Trinamool workers beat up his party's cadres and leaders.
However, Trinamool members from the area claimed that two of their party activists were beaten up by the CPI-M cadres.
A 10-hour shutdown has been called in Kamarhati municipality area on Wednesday in protest against the incident. The area goes for civic polls on April 25.