Suspected tribal rebels have shot dead 11 people in attacks in Assam, where tension has run high during a drawn-out general election, officials said on Friday.
Police said they suspected militants from the Bodo tribe were behind the attack in a region where tension between ethnic Bodo people and Muslim settlers spilled over two years ago into clashes in which dozens were killed and 400,000 fled their homes.
Bodo representatives argue that many of the Muslims are illegal immigrants from neighbouring Bangladesh encroaching on their ancestral lands, and election candidates including front-runner Narendra Modi have called for tighter migration controls.
In one of the incidents, eight people were killed by a group of suspected Bodo guerrillas.
In the other, three members of one family including two women were shot dead, and a baby was wounded, said a senior police officer in the state's main city, Guwahati.
Voting was held over several days in Assam to help security forces handle violence from any of the separatist or tribal militant groups active in the state.
Polling in the Bodo region ended on April 24, in what residents say was a tight race between a Bodo and a non-tribal candidate, although results from the five-week national election are not due for another two weeks.
Modi, the prime-ministerial candidate of the Bharatiya Janata Party (BJP), said last week that illegal immigrants from Bangladesh in the nearby state of West Bengal should have their "bags packed" in case he came to power, accusing the state government of being too soft.
Arun Jaitley, the BJP's leader in the upper house of parliament in New Delhi and a strong contender for finance minister should the party come to power, denied that Modi's comments risked stirring communal tensions in the northeast.
"It just shows a determination that we want to stop infiltration. Any government should try to stop that," Jaitley told reporters in the capital on Friday.
In Assam, the BJP condemned the attack and accused the state government, led by Congress, of not protecting its citizens.
"I call upon all parties not to communalise the issue, but to work for restoration of peace immediately," said Sarbananda Sonowal, leader of the BJP in Assam.
Police reinforcements were sent to the two districts where the attacks took place, and could be seen in television footage patrolling with automatic rifles.
"The authorities will take firm action against those involved in this crime," said state government spokesman Nilamoni Sen Deka.
Two years ago, Assam's state government was criticised for not acting quickly enough to stop intercommunal clashes, which triggered sometimes violent protests by Muslims in cities across
About 30,000 migrants from the northeast temporarily returned home after threats of reprisals by Muslims circulated by text message.