Burrabazar saw more explosions on the election day than any other pocket in the city, each of them serving as a reminder of the Trinamul Congress's desperation to gain a foothold in the trade hub.

The ruling party had lost in all six wards of Burrabazar in the 2010 civic elections. In last year's general elections, too, Trinamul had trailed in the wards, which are part of the Calcutta North constituency.

In the last civic polls, the BJP had won wards 22, 23 and 43. The CPM had won wards 18 and 21 and the Congress, 45.

"Burrabazar kisi bhi haal mein lena hai (we have to get Burrabazar at any cost)," a Trinamul leader had told Metro on Friday night while putting final touches to the party's poll-day strategy in the area.

On Saturday, party supporters tried every trick in the voting trade - firing, hurling bombs, jamming booths and attacking rivals - to wrest the area, several Trinamul leaders admitted on condition of anonymity.

The attempts at intimidation started within a couple of hours of the start of the polling. Three crude bombs exploded near 5 Council House Street, in front of a camp office of the Congress in Ward 45, around 9am.

Within an hour, Trinamul workers in Maheswari Bhavan on Kalakar Street allegedly heckled the BJP candidate in Ward 22, Meena Devi Purohit, and assaulted two of her aides.

"She is the most important face of the BJP in Burrabazar. We knew if we could scare her, the other candidates and BJP workers would not put up much resistance," a Trinamul candidate in the area said.

The intimidation tactics were scaled up shortly after noon.

Bikers threw two crude bombs in front of a cluster mobile unit comprising personnel of Calcutta police, rapid action force and central forces at Tara Sundari Park. The explosions scared away genuine voters from the neighbouring polling booths. A little later, three more crude bombs were hurled in Jorabagan in Ward 24.

"Trinamul knows it cannot beat me by fair means. That is why they are resorting to violence. But I will not give up so easily," said Purohit.

But why is this small pocket so important for the Trinamul Congress, which pollsters and even opposition parties believe would sweep the elections?

Figures - six wards and 1.30 lakh voters - hardly reveal the importance of the area to political parties.

Businessmen in Burrabazar say the trade hub's real importance lies in the fact that it has long been a source of funds for the parties and kickbacks for leaders.

"Parking of vehicles alone fetches more than hundred crores in the area every year. You can imagine how much money is there in the wholesale businesses involving spices, ghee, potatoes and onions. Then there is hawala and illegal construction," said a wholesaler of turmeric on Armenian Street, off Rabindra Sarani.

The area is more important for Trinamul now than it has ever been.

"Kickbacks from chit funds have dried up but the party is still in need of funds to maintain its organisation and fight elections. The Assembly elections are due in a year. If the party wins all the wards in Burrabazar, it won't have to worry about funds for the next year's polls," said a Trinamul leader in central Calcutta.

That explains why Trinamul started its preparations to win Burrabazar early. Chief minister Mamata Banerjee formally started her civic election campaign with a meeting on Kalakar Street, the nerve-centre of the trade hub, on April 10. The party also fielded strong candidates and local faces, unlike in 2010.

For example, Trinamul has fielded Dinesh Bajaj, a prominent Marwari face, against Meena Devi Purohit in Ward 22. The ward has been sending Purohit to the civic house since 1995.

Party sources said Bajaj, who was "penalised" for the party's poor performance in 2010 and was denied an Assembly election ticket in 2011, was asked to ensure the party's victory in the other Burrabazar wards as well.