The market and shops in Sonarpur, on the southern fringes of the city, were closed on Tuesday to protest the murder of local trader Dilip Maity.

The businessmen were upset that police did not make arrests for the murder, which took place at 6 am. Police suspect that business rivalry led to the killing. Maity, a potato wholesaler, was a partner of a cold storage.

He was on his way to the market when four persons attacked him with sharp weapons near Saheb Bagan.

The assailants escaped before anybody could put up any resistance. Bystanders took Maity to MR Bangur Hospital, where he succumbed to his injuries.

Soon after news of the murder spread, local traders and residents went to the police station and demanded that the killers be arrested. They alleged that crime had registered a spurt in Sonarpur and repeated requests to the police have yielded no result.

Tapan Sen, a local trader, complained that it was quite risky to carry money at night in Sonarpur.

?Some armed youths recently snatched money from a trader who was travelling in an autorickshaw, injuring him in the process,? he said.

Local Trinamul Congress legislator Nirmal Mondal, who also went to the police station, accused the police of not doing enough to check crime.

A few months ago, Mondal was injured by criminals, who are yet to be arrested.

?After every incident, police make arrests that are in no way connected to it. We have complained to the district superintendent of police, South 24-Parganas, without any result,? Mondal said.

Additional superintendent of police (industrial) Rajesh Subarno claimed that police had obtained vital clues about the murder and arrests were likely soon.