New Delhi: Bangladesh poses a "serious threat" to India's national security by encouraging illegal immigration on a "massive scale" and propagation by fundamentalist elements in that country that Indo- Bangla border needs to be changed, Border Security Force (BSF) Director General Ajai Raj Sharma said on August 8.

"It is very ironical that Bangladesh, which owes its very birth to the sacrifices made by our security forces, is today posing a serious threat to our national security by encouraging illegal infiltration of Bangladesh nationals into the country on a massive scale," he said in his K F Rustamji lecture in memory of BSF's first Director General.

"Fundamentalist elements in Bangladesh have been propagating that the border defined at the time of partition is no longer relevant and needs to be changed on account of demographic changes brought about by large-scale illegal migration in the past few decades," Sharma said, adding it was a "matter of serious concern".

He said some of the Bangladeshi intellectuals have claimed all the North Eastern states of India as a "natural hinterland" to accommodate the ever-expanding population of Bangladesh which has the highest population density of 750 per sq km.

"In this context, it is interesting to note that a group of intellectuals in Dhaka are seeking to legitimise the migration of its people to the adjoining North Eastern region of India by invoking the theory of 'Lebensraum' (German word) - meaning living space," the BSF chief said.

PTI