Maharashtra police chief Datta Padsalgikar, then with a central intelligence agency, was the first to alert Mumbai police that Pakistan was behind the 26\/11 attack, a senior official said Sunday. Speaking at the launch of a book written by Ramesh Mahale, the chief investigation officer of the Mumbai terror attack, Joint Commissioner of Police (Law and Order) Deven Bharti said police were groping in the dark before Padsalgikar made the revelation. "Initially we thought it was a gang war, but later got a call from Padsalgikar, who was then on central deputation. He informed us that it was a terror attack by Pakistan," Bharti said. "We were groping in the dark sans any information about the attackers," the senior IPS officer said. Padsalgikar, who released the Marathi book, '26\/11-Kasab ani Mi' (26\/11-Kasab and I), appreciated Mahale for his investigation of the 26\/11 attack. "It was due to the tenacity of Mahale and the manner in which he conducted the 26\/11 investigation, that we could conclusively establish that Pakistan was behind the terror attack," Padsalgikar said. Speaking on the sidelines of the event, Mahale told PTI that after the attack, people were scared to come forward as witnesses because they feared gangster Dawood Ibrahim. But later hundreds, including a five year old child, came forward to testify in the case, he said. Mahale was also part of a select police team, which was tasked with shifting terrorist Ajmal Kasab from the high security 'Anda Cell' of Arthur Road prison in Central Mumbai to Yerwada Central Prison in Pune.