The investigation into the serial blasts in Bengaluru has intensified with the police on Sunday questioning an unknown number of people as the needle of suspicion still pointed towards banned outfit Students Islamic Movement of India, with the crack team pursuing leads.

The Bengaluru police are also in touch with their Ahmedabad counterparts following reports that the blasts there on Saturday were similar in nature to that took place in Bengaluru a day earlier.

"We are anticipating a report from the Gujarat government," a senior police official said.

The crack team headed by Joint Commissioner of Police Gopal Hosur, entrusted with the task of uncovering the plot, is in the process of piecing together the clues.

Bengaluru police are leveraging on the expertise of the National Security Guards and forensic experts to pin down the perpetrators of the blasts.

The cement pots used in the explosions in Bengaluru has given rise to the argument that the perpetrators had "local support".

Unlike the Ahmedabad blasts, no group had so far claimed responsibility to the explosions in Bengaluru.

Chief Minister B S Yeddyurappa said the time had come to put up a united face, irrespective of party affiliations, to put down acts of such nature.

He said the Centre should infuse strength in state governments to fight the menace of terrorism.

The state government is expected to make a statement on the ongoing investigation in the blasts case, in the sssembly which is in session.

Meanwhile, there were at least three hoax bomb calls in the day. One said a bomb had been planted near the house of Kannada actor Vishnuvardhan, another said it was at Garuda Mall and the third one said it was at K C General Hospital.

Senior police officials, including DGP R Srikumar, on Saturday night visited Channapatna in Ramanagara district, where a blast had taken place on July 24, but had largely gone unnoticed.

This blast was ignored because it was thought to be of no consequence and was believed to be part of quarrying or some other harmless purpose, according to police sources.

"Remnants from the spot have been taken. It was similar to the blasts that took place in Bengaluru on Friday. Ammonium nitrate was used there (channapatna)", a senior police official said.

Meanwhile, an elite expert team on explosives from the Centre met Yeddyurappa and held discussions with him, official sources said.

A team from the National Security Guards is already sharing its expertise with state police to crack the case.