GUWAHATI, Jan 6: Seven people were killed on Saturday in a landmine explosion in India's insurgency-wracked northeastern state of Assam, bringing the death toll from two days of violence to 55, officials said.

In the latest attack, five policemen and two officials were killed as they were returning from conducting local polls in Karbi Anglong district, 260 kilometres from Assam's main city of Guwahati, police said.

“Suspected rebels of the Karbi Longri Liberation Front fired indiscriminately at the vehicle soon after the blast,” senior police official A. Baruah said by telephone.

The group is one of several separatist groups operating in Assam, northeast India's most populous state known for its oil reserves and tea crops.

Earlier on Saturday, members of the rebel United Liberation Front of Asom (ULFA) shot dead 19 Hindi-speaking migrant workers in two separate attacks, officials said.

The deaths on Saturday followed a series of attacks late Friday in the state that left 29 people dead.

Almost all of the victims of Friday's violence were also Hindi-speaking migrants, mainly daily wage earners and small traders, police said.

The authorities have blamed the ULFA, which is fighting for a separate Assamese homeland and demanding the expulsion of all non-Assamese people, especially those from the Hindi-speaking northern belt of India.

Indian Prime Minister Manmohan Singh condemned the killings as an “act of cowardice and inhumanity”, while Home Minister Shivraj Patil called an emergency meeting on Saturday in New Delhi to discuss strategy.

“The killing of innocent people will not be tolerated,” Patil said.

Since peace talks collapsed between New Delhi and the ULFA rebels last September, Assam has witnessed a series of deadly attacks that authorities have blamed on the outlawed group.

Junior home minister Sriprakash Jaisawal was to head to Assam on Sunday for an “on-the-spot study of the situation,” a government official said.

Assam chief minister Tarun Gogoi denounced the upsurge in rebel violence -- the worst in at least three years -- as “inhuman attacks on innocent people”and imposed a high security alert.

“Security offensives against the militants have been intensified,” he said.

Some 1,000 paramilitary soldiers were moved into the three affected districts and the Assam government has sought extra troops to deal with the flare-up in violence, the chief minister said.

On Friday, the rebels fired at shops and businesses and set off an explosion near a tea garden.

“We fear more such attacks and are really worried for our lives. We have been living in Assam for decades but now we don't know whether to stay or flee to safer areas,” said Rajesh Tiwari, a Hindi-speaking coal trader in Tinsukia.

In 2000, the ULFA killed at least 100 Hindi-speaking people in a series of attacks after vowing to free the state of “non-Assamese migrant workers” who they say take away their jobs.

“The attacks were reminiscent of the ones we saw in 2000 and now there's a sense of panic,” said Hariprasad Gupta, another trader in Tinsukia who hails from the Hindi-speaking eastern state of Bihar.

The immediate trigger for the new attacks was the killing of five top ULFA leaders by Indian counter-insurgency forces in the past week and the arrest of two senior rebel leaders, said Tinsukia district magistrate Hazarika.—AFP