The mastermind behind the pre-Diwali blasts in Delhi in October 2005 is suspected to be the brain behind Tuesday's serial explosions in Mumbai's suburban trains, police sources said on Thursday.

Rahil, a Lashkar-e-Tayiba operative who is suspected to have planned and executed the pre-Diwali Delhi blasts that killed over 60 persons in October 2005, is thought to be the key person involved in planning Tuesday's blasts, they said.

Mumbai police has shortlisted Rahil and his associate Imtiaz along with one Zaibuddin Ansari as the prime suspects on the basis of information gathered from independent sources and intelligence agencies, police sources said.

While intelligence agencies who have been tracking Rahil and Imtiaz for a long time now, traced them last in Bangladesh, Ansari, who is wanted in connection with the Aurangabad arms and explosives case, is also suspected to have fled to Bangladesh.

The police suspect that since Rahil, Imtiaz and Ansari have affiliation with banned LeT, they could have jointly planned and executed the blasts in Mumbai.

Since Ansari's links with outlawed Students Islamic Movement of India have already been established by the ATS, it is suspected that the blasts were jointly executed by a LeT module with the help of SIMI, sources said.

Inputs from intelligence agencies have also revealed names of two more persons Faiyyaz Khan and Bashiruddin Siddiqui, who is stated to be resident of neighbouring Thane district, but no further clues about their involvement in Tuesday's blasts.