"At this stage, we can say that we have specific doubts and suspicion on one or two groups; we have our teams which are investigating on them, the contacts they have, the network they have," City Police Chief M N Reddi told reporters here. ' He said these are "sleeper cells not based in but outside, we are collecting information on them and network behind them."
A woman was killed and three others injured in the blast triggered by an Improvised Explosive Device (IED) in front of a popular restaurant on a busy road in the heart of the city on December 28.
Stating that Special Investigation Team (SIT) is probing the case, Reddi said "the case is being reviewed by the officials at the senior level; I'm also reviewing it constantly."
He said there is no "specific development in the case so far. No specific individual reference can be made till now," he added.