After the Assam Congress’s jibes against the BJP’s candidate for the Dholai by-election, raising questions about his background and asking if he is a “Bangladeshi”, Chief Minister Himanta Biswa Sarma on Tuesday accused the Opposition party of trying to put Bengali Hindus “in danger”.

Dholai is one of five Assembly constituencies in Assam where bypolls will be conducted on November 13. It is part of the primarily Bengali-speaking Barak Valley, which shares a long border with Bangladesh.

The seat became vacant after five-time MLA Parimal Suklabaidya from the BJP, who was also a minister in the Assam Cabinet, was elected from the Silchar parliamentary seat in the recent Lok Sabha elections.

In the by-election, the BJP’s Nihar Ranjan Das is pitted against the Congress’s Dhrubajyoti Purkayastha, whose father Digendra Purkayastha was a two-time MLA from the seat in the 1970s and 1980s.

On the campaign trail in Dholai on Sunday, Assam Congress chief Bhupen Borah had questioned whether Nihar Ranjan is a “Bangladeshi”, drawing from comments that had reportedly been made earlier by senior local BJP leader Amiya Kanti Das after he was denied a party ticket.

“Amiya Kanti Das had said publicly that the BJP’s Dholai candidate, Nihar Ranjan Das, is a Bangladeshi. Who had said it? A BJP leader who is close to the Chief Minister… The Chief Minister should tell the people of Assam why the BJP has given a Bangladeshi candidature here… This is not a small thing. This is not a joking matter…,” said Borah.

Nihar Ranjan, a lawyer who has been with the BJP for over two decades, has rubbished the claims. He told The Indian Express, “These are completely false things being said and shouldn’t even be given any importance. This is just the style of the Congress. There is no truth to it.”

Amiya Kanti Das, who has been the vice-president of the BJP’s Cachar district unit, had left the party after Nihar Ranjan was announced as the party’s candidate and had submitted nomination papers as an Independent. However, he went on to withdraw his papers and rejoined the BJP after the intervention of the party leadership. He had been reported as saying in a meeting in Dholai that Nihar Ranjan’s parents are residents of Bangladesh.

On Tuesday, Himanta Biswa Sarma addressed two public meetings in Dholai – his first in Assam in the run-up to the bypolls. He lashed out at the Congress for raking up the issue.

“By saying such things, the Congress is trying to put people in danger… By raising such issues, the Congress party is trying to open cases anew against Hindu Bengali people. We have solved problems, but the Congress is trying to open an issue anew… Saying these things will not be just Nihar’s issue, it will be an issue for lots of people,” he said.

Citizenship issues are a sensitive matter in the Barak Valley, which shares an over 125-kilometre border with Bangladesh and has seen a large Bengali Hindu population migrate to it after Partition. The BJP in Assam had pitched the Citizenship (Amendment) Act as a means to bring relief to Bengali Hindus, who make up a major support base for the BJP.

While a very small number of people have applied for citizenship under the CAA, the Assam government had earlier this year instructed the state’s border police to not directly refer citizenship cases of “Hindu, Sikh, Buddhist, Jain, Parsi or Christian” people, who entered India before the end of 2014, and to instead encourage them to apply for citizenship under the CAA.

On the jibes against Nihar Ranjan, CM Sarma further said, “Be it Amiya Kanti Das who brings it up, or you or me, if these things are discussed, notices will go to the houses of another 10 people. Another 100 people will have to come to tribunals. Who will suffer? He (Nihar Ranjan) has all his papers…his name is in the NRC… Nihar babu will not suffer because of this, but 10 other people will. Congress is doing politics here so that there is again oppression of Hindu Bengali people.”