Nearly 100 Hindi-speaking people have been killed in the past six weeks in the north-east Indian state of Assam.

In an attack on Thursday, 30 people died when heavily armed militants opened fire on them.

The Assam Chief Minister, Prafulla Kumar Mahanta, has accused the main separatist group in the state, the United Liberation Front of Assam (ULFA), of being responsible for the attack with the aim of destabilising his government.

The group, however, has denied the allegation.

But if some of the ULFA militants, who surrendered last week, were to be believed the recent attacks against the Hindi-speaking settlers have been planned and executed by the group.

One of them, Ramen Nath, claimed in an interview with the BBC he was part of a group of three who planned a wave of attacks against the settlers.

Army intervention

But why target the Hindi-speaking population alone, in a state which has witnessed massacres of Bengali settlers in the 1980s and 1990s?

Nath's explanation is two-fold: the group wants the president's rule in the state so that the army is called out (thus lending credibility to the chief minister's assertion that ULFA wants to destabilise his government).

They suspect the army, as has happened in the past, will commit human rights violations, which could then be exploited by the group.

The other reason for targeting the Hindi-speaking people, Nath says, is because the settlers support the Bharatiya Janata Party (BJP), which in the group's view, wants to impose the Hindi-dominated mainland culture on the distinct Assamese society.

Bloody history

Irrespective of the validity of Nath's claims, Assam and indeed the other six states of the north-east share a history of intolerance against hundreds of thousands of settlers, who dot the verdant hills and lush plains of the region.

Mr Mahanta, who led a bloody campaign against Bengalis (mostly from Bangladesh) in the 1980s, was catapulted to power in the wake of the infamous Nellie carnage in which more than 7,000 Bengalis were killed.

The Bengalis, Nepalis and Hindi-speaking people are often dubbed as foreigners and outsiders because the indigenous people of the region, who are mostly tribal, fear that if their influx continued they will be devoured by the so-called outsiders in the near future.

They cite the examples of the region's Tripura and Meghalaya states, where the indigenous people, in the majority in the 1950s, have been reduced to a minority status now.

That is why, many analysts say, the region is in the grip of separatist movements and ethnic clashes.