* Tensions high amid election calls for migration control
* Bodo region saw rioting and mass flight two years ago
* Election front-runner Modi's BJP denies stoking tensions (New attack, death toll rise, curfew imposed)
By Biswajyoti Das
GUWAHATI, India, May 2 (Reuters) - Suspected tribal rebels have shot dead 22 Muslims in attacks in India's northeasterly tea-growing state of Assam, where tension has run high during a drawn-out national election, officials said on Friday.
A dusk-to-dawn curfew was imposed on Friday and 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 they 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 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, 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 the 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 the Hindu nationalist 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 attacks and accused the state government, led by India's ruling Congress party, 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 inter-communal clashes, which triggered sometimes violent protests by Muslims in cities across India.
About 30,000 migrants from the northeast temporarily returned home after threats of reprisals by Muslims circulated by text message. (Writing by Frank Jack Daniel and Sanjeev Miglani; Editing by Kevin Liffey and Andrew Heavens)