Three men died in separate road accidents across the city between Monday evening and Tuesday morning.
Two of them were riding motorcycles while the third was a pedestrian, police said.
Aman Kumar Shah, 35, an air-conditioner mechanic and a resident of BL Saha Road in New Alipore, was riding along Tollygunge Circular Road near Mahabirtala around 3.15am when an unidentified vehicle allegedly hit him.
The police said Shah was riding without a helmet and was thrown off his vehicle.
He was rushed to a hospital where he was declared dead. His friend, who was riding pillion, survived the crash.
In another accident, an unidentified vehicle hit a motorbike on APC Road near Khanna Market around 1.50am on Tuesday.
Pankaj Hela, 40, who was riding pillion on the two-wheeler, fell on the road and sustained fatal injuries. Hela, a resident of Garcha First Lane, near Ballygunge, was declared dead at RG Kar Medical College and Hospital. He was wearing a helmet.
In both cases, the police had yet to identify the vehicles that hit the motorcycles.
The third accident was reported on Bhupen Bose Avenue in north Calcutta, where a man living on the footpath was hit by a truck on Monday evening.
Officers of Shyampukur police station have seized the vehicle and arrested the
driver.
The deceased had not been identified till Tuesday evening.