By Subir Bhaumik
BBC News, Calcutta
Suspected separatist rebels have carried out a grenade attack on a computer shop in India's north-eastern state of Assam, injuring at least 24.
Police said they suspected the involvement of a faction of the rebel group of the Bodo tribe, the National Democratic Front of Bodoland (NDFB).
The NDFB is in negotiations with the Indian government on its demand for a separate homeland for Bodo tribes.
But a faction of hardliners has broken away from the leadership.
The faction was suspected of being involved in serial bombings that rocked Assam on 30 October last year, leaving more than 80 people dead.
On Friday, two suspected NDFB rebels hurled a grenade at the shop in the Uttarborbeel market in Howraghat in Karbi Anglong district.
Local police said that seven of those hurt were in a critical condition.
After last year's bombings, most leaders and activists of the NDFB parted ways with the hardliners and expelled the chairman, Ranjan Daimary, who is opposed to the negotiations.
Assam police chief GM Srivastava told the BBC that Ranjan Daimary was trying to revive the hardline faction to scupper the talks.
In a separate incident on Thursday, a bomb attack damaged rail tracks near the hill town of Diphu in the same Karbi Anglong district. The blast just missed the Rajdhani express service.
Police said they suspected a small rebel group of Karbi tribesmen, the Karbi Longri National Liberation Front (KLNLF), of carrying out that attack.