Uttar Pradesh government today transferred investigation of Varanasi blast to the Anti Terror Squad of the state police.
"Investigation into yesterday's blast, which was till now being done by Varanasi police, has been handed over to the ATS for further probe," Additional Director General of Police (Law and Order) Brij Lal told reporters here.
Though Indian Mujahideen has claimed responsibility of the blast, he said it was premature to name any organisation, person or module behind the attack.
"As of now we cannot say with surety who is the person, organisation or module behind the blast," he said.
Lal said the mail, reportedly sent by IM, originated from Navi Mumbai. "The mail was sent by using a wi-fi connection of Mithlesh Thakkar, a resident of sector 17, Wasi Navi Mumbai."
The Mumbai police said the system was unsecured as it did not have a password, the ADG pointed out.
He said teams of forensic science laboratory, Special Task Force besides experts of the central agencies visited the spot for a close examination. "No circuit, battery, remote operated device or shrapnels were recovered from the spot.
Whatever evidences were collected have been sent for chemical analysis after which it will be clear what explosive was used," he said. The ADG said injury caused to the people was also not due to shrapnels. "There is a possibility that the explosive might have been placed under a stone at the ghat, but it is a matter of investigation," he added.