The Tripura government wants three battalions of the army to be redeployed in counter-insurgency operations to neutralise the activities of the banned National Liberation Front of Tripura and All Tripura Tiger Force.

The request by the state's Chief Secretary V Thulasidas came after the two outfits killed at least 40 people last week in four different incidents.

The three battalions were withdrawn from Tripura for deployment in Operation Parakram last year. "The counter-insurgency grid is incomplete without the presence of the army," Thulasidas said.

Although the Border Security Force mans the international boundary with Tripura, the Central Reserve Police Force and the Tripura State Rifles conduct the counter-insurgency operations. "Our force levels are not adequate to meet all the requirements," Thulasidas said.

Alarmed by the sudden spurt in violence, the Tripura government has also been pressurising the Centre to take up with the Bangladesh government the issue of camps run by these outfits inside that country.

Meanwhile, the latest killings have sparked off an exodus of non-tribal Bengalis from the interiors of the state. The latest round of violence is seen as part of efforts at ethnic cleansing undertaken by the militant outfits since 1993, when the second and bloodier phase of Tripura's insurgency began.

Analysts in the state mark the first phase of exodus with the killings of non-tribals by the erstwhile Tripura National Volunteers. TNV militants surrendered en masse in 1988.

The next phase of killings of non-tribals was launched by NLFT and ATTF in 1993 and led to the exodus of more than 200,000 non-tribals from interior areas of the state in all three districts.

The worst affected were villages in Bishalgarh and Sadar subdivisions where many non-tribals had been resettled on government land under the rehabilitation scheme for erstwhile refugees from the then East Pakistan. Similar exodus took place from interior areas of Khowai, Kamalpur, Longtarai valley, Kanchanpur, Gandacherra and Udaipur subdivisions.