The blasts at Agartala have raised concerns among Intelligence Bureau officials that the latest incident may be a new pattern in the war against India.

IB sources say that the nexus between terror outfits in the northeastern part of the country and the Bangladesh-based Harkat-ul-Jihad Islamiya has been brewing for sometime now.

HuJI which is alleged to have played the key role in the Hyderabad twin blasts and the blasts at Ajmer has set up nearly 25 training camps in the northeast. Over the past few years, Students Islamic Movement of India too is alleged to have sent its members for training to some of these camps.

IB reports state that the Lashkar-e-Tayiba was trying to take strategic advantage of India's porous border with Bangladesh in order to carry out terror activities. The LeT was finding it increasingly difficult to penentrate into India through the western side and hence set up HuJI based out of Bangladesh to enter the country through the eastern side.

The strategy adopted by HuJI was simple. They took advantage of the fact that there was growing unrest in the northeastern states and thanks to this several terror outfits had come up. However the problem that the NE based outfits faced was the supply of arms and also men to execute attacks.

The HuJI in coordination with the LeT used this an opportunity to destablise India. In association with rebel groups in the northeast, and the United Liberation Front of Asom in particular, training camps were set up. While the arms and ammunition and to a large extent the men were provided by HuJI the internal groups focused more on providing logistic support.

The main entry point is Assam which shares a porous border with Bangladesh. Infiltrations are easier through this side since the ULFA provides logistical support. Reports suggest that there are nearly 1.5 crore Bangladeshis living in the northeast.

IB sources also say that the income levels of these Bangladeshis is very low and taking advantage of this fact, terror groups use them as sleeper cells. Over the years the sleeper cells or the tanzeems as the Bangladeshis call them have been set up extensively in Assam and Tripura.

The work undertaken by these sleeper cells includes gathering intelligence, shallow penetration and trans-border operations, deep penetration itinerary operations and specific sabotage and subversion operations.

The IB says that while northeastern states have always been troubled by internal unrest, the latest blasts at Tripura was more of an announcement by external forces to show their might in India.

The IB warns that security agencies have to constantly be on the lookout and deal with the issue with utmost seriousness. A clean up operation of illegal migrants in northeast is the need of the hour since most of them are actively involved in the tanzeems that have been set up over there.