Inspector General of Police (Law and Order) S.N. Singh said that suspected cadres of the anti-talk faction of the United Liberation Front of Asom (ULFA) carried out the attack around 6.45 p.m.
However, the grenade exploded in air and therefore there were not many causalties, S.N Singh said.
"The injuries are of minor nature and the condition of all the four victims is stable now," said a police officer.
An operation had begun to trace out the culprits, he added.
There had been inputs ahead of the Independence Day (Aug 15) celebrations that the the anti-talk faction of the Ulfa led by its commander-in-chief Paresh Baruah might try to disrupt the celebrations.
On Independence Day, militants of the anti-talk faction of National Democratic Front of Bodoland (NDFB) had triggered a grenade blast at Kokrajhar town of lower Assam.
--IANS (Posted on 22-08-2013)