Chief minister Mamata Banerjee on Thursday renewed her verbal attack on the Border Security Force (BSF) that guards the India-Bangladesh border as her party continued to exert pressure on the BJP over the deaths of four minor boys at a BSF trench-digging site in North Dinajpur’s Chopra.

“What happened in Chopra? The BSF is answerable. I want punishment for (all those involved in the mishap in) the BSF. The job of the BSF is to protect the borders… but they are campaigning for BJP,” Mamata said in the Assembly.

In the course of her speech, she held a photo that claimed it showed BSF personnel with a saffron bag.

“What is the BSF doing with a saffron bag? I am furnishing the photograph here for the consideration of the members of this House,” said Mamata.

Over the past couple of years, Mamata, along with her nephew and Trinamul’s national general secretary Abhishek Banerjee and other party leaders have time and again spoken against the central security force posted on the international border, calling it trigger-happy and highhanded.

She has unequivocally opposed the Centre’s decision to increase BSF’s jurisdiction from 15km to 50km within the Indian territory from zero point and passed a bill against it in the Bengal Assembly.

On Monday afternoon, four boys, aged between five and 12 years, died as a heap of earth fell on them while they were near a trench at Chetanagach, a village in Chopra close to the Bangladesh border. The BSF had engaged an excavator to deepen the trench dug to check cattle smuggling when the incident happened. Villagers had alleged that the BSF did not take precautions at the work site, which Trinamul took up.

Mamata said that the Narendra Modi government at the Centre sent 334 teams so far to Bengal probe various incidents and allegations. “Why are they not sending a team now (to Chopra)?” she asked.

A delegation of senior Trinamul leaders reached Raj Bhavan and met Governor C.V. Ananda Bose on the Chopra issue.

State minister Chandrima Bhattacharya, who was a member of the delegation, later said they submitted a memorandum to Bose and requested him to visit Chopra.

“We have mentioned to the governor that the BSF’s carelessness cost the four boys their lives. We urged him to visit Chopra and informed the Union home minister (Amit Shah) so that the bereaved families get justice. He (Bose) has told us that he will visit Chopra,” said Bhattacharya.

They also alleged that even though the BSF took up the trench work, they didn’t inform the administration or the police. “They brought an excavator to dig the trench near the border but the administration and the police had no inkling about it,” she said.

In Chopra, the five-member team of the West Bengal Commission for Protection of Child Rights (WBCPCR) led by chairperson Tulika Das, which reached on Wednesday, met the affected families in Chetanagach and visited the spot where the incident happened. Das told newspersons that they also met local BSF officials on Wednesday evening.

“We told them that their negligence led to the mishap. Their officers have assured us that in future they would take necessary precautions,” said Das.

She added the WBCPCR would send recommendations to the BSF and serve it a showcause letter for the incident.

“The BSF should make public announcements before taking up such work. People should be alerted so that the villagers, especially children, stay away from the work site. Also, the BSF should post their men at the spot to prevent people from entering the work site,” she said.

North Dinajpur district Trinamul continued its sit-in demonstration in front of the BSF camp in Daspara of Chopra, demanding compensation, for the third day on Thursday.

“Our demonstration will continue until the BSF hands over compensation to all the four families,” said Hamidul Rahaman, the Trinamul MLA of Chopra.

The BJP has hit back.

Raju Bista, the BJP’s Darjeeling MP (the Chopra Assembly constituency falls under his Lok Sabha seat), said that the ruling party of Bengal was trying to politicise the deaths.

“Mamata Banerjee and Trinamul are trying to put national security at stake by raising baseless allegations against the BSF. They are trying to reap political dividends from an unfortunate incident,” Bista, also a BJP national spokesperson, said.