In the city's Beliaghata area, clashes broke out between two groups of people, following which the police resorted to mild lathicharge to disperse them.
BJP's Jorasanko candidate Meena Devi Purohit alleged that the crude bombs were hurled at her vehicle while she was touring different polling booths.
Over 84.77 lakh voters will decide the political fate of 283 candidates in this phase.
Security measures have been heightened in view of the violence in the previous phases, particularly the death of five people in Cooch Behar in the fourth round of polling.
According to the data, South Kolkata where polling is being held in 4 constituencies, recorded the lowest of 13.07 per cent. Malda with 6 constituencies recorded a polling of 18.85 per cent followed by South Dinajpur where 18.77
Over 1.03 crore voters will decide the political fate of 306 candidates in this phase.
As many as 17.1 lakh voters are expected to exercise their franchise in 2,470 polling stations. Voters above 80 years have been extended the postal ballot facility.
The Chief Minister had said that she will hold a protest rally in Cooch Behar on Sunday against the firing incident and visit the homes of the deceased.
She alleged this was part of a conspiracy hatched by the Union home minister.
The youth, identified as Anand Burman, was dragged outside polling booth number 85 in Pathantuli area of Sitalkuchi while voting was underway and shot dead.
Polling began at 7 am for 44 seats in the fourth phase of the West Bengal Assembly election amid tight security.
Villagers came out of their houses and exercised their franchise to vote violating the prohibitory orders under Section 144.
Elections are being held for 515 ZPTC seats and 7220 MPTC in the state from 7 am to 5 pm. In 660 ZPTC, elections are being held for 515 ZPTC seats and 2058 candidates are in the fray.
Elections in Puducherry, which is currently under President's Rule, is mainly between the Congress - DMK alliance and NDA comprising All India NR Congress, AIADMK and BJP
Even before polling opened at 7 am, people could be seen eagerly queuing up before the polling stations.
Kerala, Tamil Nadu and Puducherry are voting on Tuesday in single-phase assembly elections.
Altogether 79,19,641 voters -- 40,11,539 men, 39,07,963 women and 139 of the third gender -- are entitled to exercise their franchise in 11,401 polling stations.