TEMPO.CO, Assam - Suspected tribal rebels have shot dead 22 Muslims in attacks in tea-growing state of Assam, where tension has run high during a drawn-out national election, officials said, Friday.

A dusk-to-dawn curfew was imposed on Friday. Soldiers deployed in the affected parts of Assam, a remote state with a history of ethnic violence and armed groups, some fighting for greater autonomy and others for secession from India.

Police said to have suspected militants from the Bodo tribe were behind the latest attacks late on Thursday into Friday 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 the neighboring 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, said officials.

In another, 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. Later on Friday, a group of militants carrying AK-47 assault rifles attacked an isolated village in the state's Baksa district and open fired, killing 11 people, most of them women and children, said police.

They burnt their huts made of bamboo and straw and threw the bodies in the fire, officers added.

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.

"It seems the Bodos wanted to teach the Muslims a lesson for supporting an outsider," said a state intelligence officer. He said half-burnt bodies with bullet wounds had been recovered from the village in Baksa district.

Modi, the prime-ministerial candidate of 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.

ANINGTIAS JATMIKA | HINDUSTAN TIMES | REUTERS