With the arrest of a Lashkar-e-Tayiba terrorist from Uttar Pradesh who had done a recce of a dozen sensitive targets in Mumbai, the Maharashtra Anti Terrorism Squad fears three or more terror modules could be operating in the financial capital and newer strategies will have to be devised for busting them.

"Considering the population of the city and the anonymity that various pockets offer, we feel there will be at least three to four more sleeper cells operational in Mumbai though it is an analytical guess," a senior ATS officer told PTI.

Greater stress will be laid on strengthening the network of informants to get more leads so that the modules are busted in Mumbai, which has been hit many times by the terrorists, including the serial train blasts in July 2006 which resulted in the deaths of 187 people, the officer, who did not wish to be named, said.

Fahim Arshad Ansari (35), born and bought up in Mumbai, was arrested by the UP Special Task Force along with seven other Lashkar men.

During interrogation, they revealed that they planned to carry out strikes in Mumbai.

Ansari, who received training at LeT camps in Pakistan-occupied-Kashmir, had started ground work in the run up to a terror strike in Mumbai.

He had rented a house in Mumbai's red light district and was searching for one more flat.

"He had also surveyed possible targets and I think he was entrusted with the logistical support being a local. Once the two hideouts were in place, more terrorists would have moved into them and following which a delivery of the explosives would have taken place," said the officer.