Till 11 am, voter turnout of 36.97 per cent was recorded from Hooghly district, 39.81 per cent in South 24 Parganas, while Kolkata South had the lowest turnout with 32.58 per cent.
The Election Commission said the overall average turnout was 38.3 per cent.
A report from Chinsurah in Hooghly district said a villager sustained head injury when he was allegedly attacked by Trinamool Congress supporters at Puin village in Arambag constituency.
N Babu, the villager, was attacked while returning after casting his vote, a police officer said.
He was rushed to Arambag sub-divisional hospital where he was released after first aid, the officer said.
Babu alleged that TMC supporters had warned him not to cast his vote the night before but he had defied them and exercised his franchise, thereby incurring their ire.
Police have arrested one TMC supporter.
A report from Canning in South 24 Parganas said two persons were injured as central force jawans used batons to disperse clashing Trinamool Congress and CPI(M) supporters in front of a booth in Kathaliya village under Bhangar constituency.
The injured were rushed to Bhangar hospital and later discharged after treatment, a police officer said.
Trinamool Congress candidate from Bhangar, Rezzak Mollah rushed to the spot and was involved in an altercation with the central forces following the incident, the officer said.
In Bahareshole village in Goghat constituency in Hooghly district, Forward Bloc candidate Bishwanath Tarak complained to the Election Commission that he was pushed around by TMC supporters who had gathered in front of a booth.
The central forces swung into action and dispersed the TMC supporters.