The BJP has adopted a two-fold strategy on Monday to exert pressure on Trinamul over last week's "atonement ritual" performed by four tribal women in South Dinajpur for joining the saffron camp.

While party leaders wrote to the President of India, the National Commission for Scheduled Tribes and the chief minister for their intervention, they also held a protest march and a public meeting in Balurghat where speakers tore into Mamata Banerjee’s party and government.

“I have sent letters to the President and to the NCST authorities and have requested their intervention for the atrocity which four tribal women had to face. The Trinamul leader (Pradipta Chakraborty) who instructed the quartet to perform the ritual is roaming freely,” alleged BJP state president Sukanta Majumdar.

Majumdar, also the MP of Balurghat, joined the protest march with party national vice-president Dilip Ghosh, district MLAs, party leaders and hundreds of supporters.

On Friday, a clip surfaced on social media showing four tribal women — Martina Kisku, Shiuli Mardi, Thakran Soren and Malati Murmu who joined the BJP a day before — performing an atonement ritual of dragging themselves for 1km after which they were re-inducted into Trinamul.

Chakraborty, then district president of the women’s wing of Trinamul, took credit for bringing the four back to the party. She was removed from her post on Sunday.

“We have seen other incidents where Trinamul has misbehaved with tribals or made derogatory remarks about them. In Assam, the President, who is also from the tribal community, took a ride in a fighter aircraft on Saturday. In Bengal, these four tribal women were made to perform such a ritual by a political party on Friday,” said Majumdar.

In Calcutta, Ashok Kumar Lahiri, the BJP MLA of Balurghat, said he wrote to chief minister Mamata Banerjee that no legal step had been taken against Chakraborty.

The BJP's moves hint that the party intends to fan the issue in tribal belts ahead of the rural polls, opined political observers.

“The votes of tribals matter in a number of districts of the state, including South Dinajpur, where tribal community forms around 17 per cent of the population. It is also the home turf of Majumdar who wants a good show in the rural polls,” said an observer.

Majumdar also alleged that a pregnant tribal woman, Sumitra Soren, 21, died without treatment at Balurghat district hospital on Sunday. Hospital authorities said they were looking into the charge.

Sujata Pakrashi Lahiri, a member of the West Bengal Commission for Women, reached Balurghat on Monday where she talked to three of the four tribal women. "We will file a report to the chairperson,” she said.

On Monday, the police took the four tribal women to the district court where they gave their statements before a judge.