By regional analyst Alastair Lawson

Like many other states in India's insurgency hit north-east, the people of Tripura have over the last five years endured thousands of abductions and hundreds of killings.

Most of this violence has been carried out by the two main separatist rebel groups, the National Liberation Front of Tripura (NLFT) and the All Tripura Tiger Force (ATTF).

Tripura is one of India's seven north-eastern states, sometimes known as the seven sisters.

It has a population of around three million - three-quarters of whom are Bengali-speaking settlers whose families mostly arrived in the state after the partition of India in 1947.

Banned

Both the National Liberation Front of Tripura and the All Tripura Tiger Force say they want independence for tribal areas of the state, which exist in all of Tripura's four districts.

Both have been been banned by the BJP-led Indian central government.

In support of their goal both groups have kidnapped political opponents and launched violent attacks on the Bengali speaking community: nearly 150 have been killed this year alone.

However, it is here that the similarities between the two rebel groups end.

The NLFT is larger and better armed. It says it is fighting not only for the removal of Bengali immigrants from the tribal areas, but also for the tribal areas of the state to become overtly Christian.

The NLFT has warned members of the tribal community that they may be attacked if they do not accept its Christian agenda.

The rivalry between the groups was clearly seen recently when the NLFT and the ATTF clashed in the jungles of Bangladesh. An ATTF commander was killed.

It is estimated that around half of Tripura's 200,000 tribal community are Christian and support the NLFT.

It is unclear where the loyalties of non-Christian tribals lie, partly because it has been alleged that they have been coerced into supporting the NLFT.

Tribal elections

Another key difference between the two groups is the decision by the NLFT to take part indirectly in recent elections to the state's tribal council elections which were boycotted by the ATTF.

The NLFT backed the Indigenous Peoples' Front of Tripura (IPFT) in the vote to the council, which rules over roughly one-third of the state's population.

The IPFT won most of the seats, and immediately announced that one of its main priorities was to redress what it described as the marginalistion of the tribals.

It warned that non-tribal people would be treated as foreigners. Thousands of Bengalis have over the last decade been expelled from areas controlled by the council. Against this background the state's Bengali-speaking community has begun retaliation attacks.

Meanwhile the Indian central government led by the BJP - which has no representation at all in Tripura - must decide whether the most effective way to end the state's ceaseless violence is by enforcing direct rule from Delhi.