The three explosions that rocked the city on Thursday was the handiwork of the banned ULFA, Assam Director General of Police G M Srivastava said.
"We had information that an ULFA cadre has sneaked into the city and was planning to carry out subversive activities on either December 31 or January one. The security was alerted and as such the attacks were not carried out in an organised manner", Srivastava told reporters here.
The outfit had plans to carry out subversive activities on a large scale but it was "foiled by our alert force".
"The security was tight, checkings were on and the bombs were thrown in a disorganised manner, except in Bhootnath area where the bomb planted in bicycle was kept in front of a shop", he said.
The DGP expressed regret that the local public were not alert enough at Bhootnath as the bomb was planted there.
The police have identified the cadre who had sneaked into the city to carry out the blasts and he was a new recruit.
He said "militants usually strike on such days to make their presence felt and send a message to the common people that they exist."