A BJP polling agent allegedly entered Kshudiram Anushilan Kendra on Thursday evening, where eight strongrooms are located, triggering allegations that electoral protocol was breached as representatives of other parties were absent at the time.

Trinamool Congress leaders Shashi Panja and Kunal Ghosh rushed to the spot and led a protest outside the venue, accusing the BJP of malpractice and alleging a lack of transparency.

Smita Pandey, the district election officer of Kolkata North, refuted the allegations and called it “absolutely untrue”.

“Postal ballots were being segregated on Thursday at Khudiram Anushilan Kendra. The postal ballots with DEO, Kolkata North, had to be segregated constituency-wise. On Friday, the postal ballots of all 152 constituencies that went to polls on Wednesday will be exchanged at Barasat, where the central clearing centre for postal ballots has been set up,” Pandey told Metro.

“It is absolutely untrue that an agent of a single political party had been allowed inside. Would any returning officer do this?” Pandey said.

Hundreds of Trinamool workers rushed to the spot and raised “Joy Bangla” slogans outside the venue as party leaders alleged that election officials had opened the strongroom for BJP functionaries without informing other political parties.

The allegations emerged a few hours after chief minister and Trinamool chief Mamata Banerjee urged all party candidates to “guard” the EVMs by sitting outside the centres to prevent a breach attempt by the BJP.

There was speculation that Mamata herself would join the protests, but she went to Shakhawat Memorial, the school that now houses the strongroom of her Bhabanipur constituency.

According to rules, only candidates can enter their respective strongrooms.

Past midnight on Thursday, Mamata told reporters outside Sakhawat Memorial Government Girls’ High School: “I got information that there was an attempt to tamper (with the EVMs). Candidates of the constituency and party agents have the right to enter the building, but only up to the locked strongroom, not inside it.”

“I heard that the postal ballots (of the Bhabanipur constituency) will be taken to Barasat. My question is, why? And if they have to be taken, the respective candidates must also be kept in the loop for transparency,” she added.

Kshudiram Anushilan Kendra houses the strongrooms for the Chowrangee, Entally, Beleghata, Jorasanko, Shyampukur, Maniktala and Kashipur-Belgachia Assembly constituencies. The eighth strongroom on the premises is for postal ballots.

Purported CCTV footage circulated by Trinamool showed a group of men and women sitting on the floor with boxes and papers around them. Sources said they were working with postal ballots.

Kunal Ghosh, the Trinamool candidate from Beleghata, said there was “complete lack of transparency” about how the agent entered the building.

“The BJP has been caught doing something wrong inside the strongroom, and that is why they are behaving like this,” Ghosh said.

Supporters of both parties engaged in a war of words and slogans outside the venue, adjoining Netaji Indoor Stadium. The police intervened to pacify them.

The BJP’s Maniktala candidate Tapas Roy and Chowrangee candidate Santosh Pathak visited the spot and denied the allegations. “All the allegations are baseless,” Roy told reporters.

Trinamool and BJP candidates later met the election officials.

“We have conveyed all our doubts to them (EC officials). We have demanded more CCTV cameras, and they have agreed,” Panja said.

Trinamool posted on X: “CCTV footage has exposed how @BJP4India, in active collusion with the @ECISVEEP, is opening ballot boxes without the presence of any relevant party stakeholders. This is gross electoral fraud being committed openly with the full knowledge and protection of the Election Commission.

“They have tried every dirty trick, name deletion, voter intimidation, Central Force terror, cash flooding, and failed miserably. Now, in sheer desperation, they have stooped to tampering with EVMs. But Bengal is not Maharashtra, Delhi, or Bihar. We will not sit silently and watch them loot our democracy.”

At a late-night press conference, chief election officer Manoj Kumar Agarwal said the incident was “unfortunate” and “baseless”.

“It (the allegations) has no basis. It is only for publicity and to create a narrative,” he said.

“The strongrooms have enough security. From tomorrow, DEOs will have to certify that all the arrangements made in the strongrooms are in accordance with the ECI guidelines,” he said.