New Delhi has accused Bangladeshi Prime Minister Begum Khaleda Zia's government of launching a covert operation to turn India's border region into a Muslim-majority zone. It says Dhaka has sent in millions of illegal migrants to pave the way for the region's secession from India. The accusation has worsened strained relations between the Muslim nation and its giant, Hindu-majority neighbour. 'The influx of Bangladeshis into Assam has escalated sharply after [Begum Zia's] Bangladesh Nationalist Party (BNP) came to power. There is a grand design behind the silent demographic invasion of the sensitive northeastern state,' said Home Minister I. D. Swamy. Citing reports by Assam Governor S. K. Sinha, Mr Swamy said the number of Bangladeshis in the border state had risen to four million. But according to Tufail Haider, Bangladesh's high commissioner in New Delhi, 'not a single Bangladeshi is staying illegally in India'. Mr Swamy said the Bangladesh government and fundamentalist Islamic groups were 'systematically flooding Assam with immigrants'. He also said Pakistan's Inter-Services Intelligence agency was behind the move to destabilise India. Indian officials said that if the 'planned and deliberate influx' continued unchecked, Muslims would eventually outnumber Hindus in Assam, resulting in its secession from India. Muslims were already in a majority in eight districts of Assam, they said. Dismissing New Delhi's charge, Mr Haider said: 'Of late, for reasons best known to New Delhi, India has levelled one ridiculous charge after another which we have refuted. And nothing can be more ridiculous than accusing the Bangladesh government of aiding and abetting the so-called influx of immigrants.' Independent analysts are blaming India for stirring up the issue to browbeat Bangladesh. Last month, India's hardline Deputy Prime Minister, Lal Krishna Advani, triggered a diplomatic row by saying there had been an increase in the activities of al-Qaeda and the Pakistan intelligence agency in Bangladesh since Begum Zia's government came to power in October last year. Even as Bangladesh dismissed the accusation as baseless and politically motivated, New Delhi handed Dhaka a list of 99 militant training camps allegedly operating in Bangladesh. New Delhi also demanded that Dhaka round up 77 insurgents from India's insurgency-gripped northeastern region who have reportedly taken refuge in Bangladesh, and repatriate Indian rebel leaders jailed in Bangladesh. Analysts said India's unexpected diplomatic offensive was provoked by Dhaka's support for Pakistan's bid last month to re-enter the Commonwealth. The strained relations have resulted in the postponement of two bilateral economic conferences. India also pulled out of a trade fair in Dhaka this month after the Bangladeshi government said it was unable to ensure the safety of the Indian participants. The arrest last week of more than 20 Bangladeshi soldiers and civilians for spying for India's main spy agency, the Research and Analysis Wing, in return for cash has heightened tensions. According to a ministry statement, Dhaka put its intelligence services on alert after an alleged spy for India revealed that the spy agency had planted agents in several Bangladeshi defence installations. BORDER TENSION India claims four million Bangladeshis live in Assam 'Not a single Bangladeshi is staying illegally,' says Dhaka Pakistan's intelligence agency is accused of interference