There's still uncertainty among Indian officials as to who is responsible for Wednesdays triple blasts in Mumbai.
Three bombs went off in separate locations in the city during Wednesday's rush hour killing more than a dozen people and injuring more than 100.
Officials have said those responsible seem to be trained in handling explosives and may have used timers to synchronize the blasts.
Wednesday's triple blast was the first terrorist attack since Pakistan militants struck in November 2008 killing more than 160 people.
The countries recently resumed peace talks and are set to meet later this month. There are reports that the recent attack was a means to disrupt the discussion to happen later this month.
However, the Pakistani government has condemned the violence shortly after the triple blasts.
The evidence gathering continues but is being hindered by a rainstorm.
Home Minister Palaniappan Chidambaram has said he wouldn't speculate about who carried out the attacks.
We are not pointing a finger at this stage,'' he said. We have to look at every possible hostile group.''
Investigators are also looking over forensic evidence and surveillance video so as to find clues that may help to determine who's responsible.
It is being reported that forensic examination of debris at the sites has indicated that ammonium nitrate, which is commonly used in fertilizer, was used in the explosives.
Voice of America is reporting that Home Secretary R.K. Singh on Friday said authorities have identified a scooter that contained one of the bombs. Investigators are also reviewing large amount of surveillance video from the sites of the explosions, looking for suspicious people are activities, according to that report.