About 50 people, mostly Hindi-speaking migrants, have been killed in two days of attacks by suspected separatists in the north-east Indian state of Assam.
Several other people were reported injured in the attacks
Police say the United Liberation Front of Assam (Ulfa) is responsible, but the rebel group has yet to respond.
A permanent curfew has been imposed in the Tinsukia district following a spate of attacks on Hindi-speaking settlers.
The government is sending a high-level team to assess the worst violence seen in the state for at least a decade.
'Act of cowardice'
Police said the rebel group attacked six colonies of Hindi-speaking labourers in the northern districts of Dibrugarh and Tinsukia within three hours.
Witnesses described groups of 10 to 15 masked and heavily armed men firing indiscriminately, sparing none - not even women and children.
By late on Saturday 48 Hindi-speaking settlers had been killed, making it the worst carnage of migrants in Assam for at least a decade.
The authorities have imposed a round-the-clock curfew in the Tinsukia district near the border with Burma, after thousands of angry residents protested against the failure of the security forces.
In the latest incident on Saturday, the suspected rebels exploded a landmine in the district of Karbi Anglong, killing five policemen and two government officials.
Indian Prime Minister Manmohan Singh condemned the killings as an "act of cowardice and inhumanity" and a government team is on its way to Assam to assess the violence.
'On the defensive'
The BBC's Subir Bhaumik in Guwahati says ever since talks between the Ulfa and the government collapsed in September, the rebels have targeted Hindi-speaking migrants, mostly from the northern state of Bihar, with bomb and grenade attacks.
Officials say the Ulfa has intensified such attacks to pressure the government into calling off its military operation against the rebel group, or at least put it on the defensive by forcing it to guard target villages.
Security officials say attacks could intensify ahead of India's Republic Day celebrations on 26 January. The Ulfa has also called for a boycott of next month's Indian National Games.
The rebels are seeking a separate homeland for the Assamese people and demanding the departure of the non-indigenous population, particularly Hindi speakers.
They have been fighting Delhi's rule in the tea and oil-rich state for the past 27 years. At least 10,000 people have died in the violence.