Chief minister Mamata Banerjee on Tuesday slammed the alleged bias against Bengali-speaking citizens of India in BJP-ruled states, wondering if Prime Minister Narendra Modi knew about this and promising to take it up with him.

Mamata was referring to recent cases where Indian Bengali speakers were picked up by the police in some states and "forcibly pushed" into Bangladesh by the BSF.

Mamata said she found out that 300-400 migrant workers from Itahar's Khisahar (in North Dinajpur) and other village were currently confined in Rajasthan, despite having valid identity and citizenship documents, and wondered if such linguistic discrimination takes place with speakers of other languages.

"Has it become a crime to speak in Bengali, the language of Rabindranath Tagore, Swami Vivekananda, Netaji Subhas Chandra Bose...? I suppose Prime Minister Narendra Modi is not aware of this development, I will draw his attention to it," Mamata told journalists at her Assembly chamber.

She added that such incidents had taken place in other BJP-ruled Delhi, Odisha and Madhya Pradesh.

The chief minister also showed from her phone some purported pictures of Bengal's residents allegedly confined in Rajasthan.

She said she was not sure how Modi felt about Bengalis, but harboured no doubt that his party and its state governments were prejudiced.

"The situation is terrible.... You speak Bengali, and you get pushback? I heard that teaching Bengali has been stopped in Delhi University.... Then tell us the language is banned in your rule.... We will take to the streets in protest," she said. "Is the Union home ministry under Amit Shah unaware of this witch-hunt against Bengali-speakers?"

Mamata said Bengal chief secretary Manoj Pant was in touch with his Rajasthan counterpart on the alleged confinement in Bhiwadi after the matter was brought to the notice of the House by Trinamool's Itahar MLA Mosaraf Hussen.

On June 16, Mamata launched a broadside in the Assembly on BJP-ruled governments in states and at the Centre over the alleged "pushback" of migrant workers from Bengal to Bangladesh, accusing the administrations of tagging people as Bangladeshis as they speak in Bengali. Several migrant workers were reported to be detained earlier this month by police in Maharashtra and Delhi on suspicion of being Bangladeshis. On being handed over to the BSF, they were allegedly pushed across the border without their citizenship status verified with the Bengal government.

Around 1.5 crore migrant workers from other states work and live in Bengal, said Mamata, but such treatment is never meted out to them as it "goes against the very basics of the core ethos of inclusive pluralism in India".

"What if such measures are taken against migrants from other states here for speaking in their mother tongue? Is speaking Bengali now deemed sacrilegious in the BJP regime?" Mamata asked, adding that around 22 lakh migrant workers from Bengal currently work and live in other states.

"If one speaks Tamil or Sinhalese in the south, will you send them to Sri Lanka? Will you send our Gorkhas to Nepal?" Mamata asked.