Assam's chief secretary, Vijendra Singh Jafa, told the BBC that Bangladesh has formally informed India about Mr Barua's arrest. He said the general secretary of the outlawed United Liberation Front of Assam, Mr Gulab Barua, also known as Anup Chetia, was arrested from somewhere in Dhaka on Friday, after being followed around for a while by the special branch.

But he said he had no details of the circumstances in which the seperatist leader was actually caught. Indian home ministry officials also confirmed the news of Mr Barua's arrest without being able to provide the details.

Officials in Bangladesh, however, neither denied, nor confirmed, the incident. Mr Jafa said the Bangladesh government had arrested Mr Barua in response to the red-corner notices issued against him and some other leaders of the United Liberation Front of Assam through the Interpol by the Indian government.

This is not the first time that Bangladesh has arrested anti-Indian seperatist leaders. In 1992, the Bangladesh Rifles arrested three senior leaders of seperatist groups from the Indian state of Manipur and handed them back to the Indian border security force.

That was when the Bangladesh Nationalist party was in power. Now, Bangladesh's ruling Awami League party, which is known to be friendly to India, has said it will not allow its territory to be used for terrorist activities against India.