GUWAHATI: A ten-year-old boy was killed and five more people injured when suspected militants lobbed a grenade into a crowded market in India's tense northeast, police said.

“Militants riding a motorcycle threw a grenade as they drove through a busy market, killing one child and wounding five other people,” senior police official Debajit Deuri told AFP.

Two of the injured were in critical condition, he added.

The attack took place in the small town of Udalguri, 71 kilometres north of Assam state's capital Guwahati.

There was no immediate claim of responsibility, but in the past police have blamed similar attacks on groups fighting for independent homelands for their tribal followers in the tea and oil-rich region of Assam.

Last year, one of the strongest militant groups, the United Liberation Front of Asom (ULFA) announced it would join peace talks with the Indian government in a move to end a 33-year-old rebellion.

A faction of the National Democratic Front of Bodoland (NDFB) militant group also recently agreed to a ceasefire with New Delhi.

Since then, factions of both groups, which oppose the peace overtures have carried out bomb and grenade attacks in the state, according to police officials.

More than 10,000 people, mostly civilians, have lost their lives to insurgency in Assam during the past two decades.

India has been wracked by separatist conflicts since its independence in 1947, with deadly insurgencies in its northwestern Kashmir region and the northeast.