Intelligence Bureau sources say the massive attack on Mumbai on Tuesday -- seven serial blasts on local trains when traffic was at its peak -- was to disturb communal harmony, just like last year's attack at the Ayodhya shrine was.

One top source said the blasts in Kashmir and those in Mumbai certainly seem corelated, though all possible angles were being probed.

Terrorism expert B Raman said the Kashmir blasts and the Mumbai blasts seem orchestrated by the same command and control.

Raman believes there is a strong possibility of Al Qaeda being behind the blasts and they could have been executed by fugitive gangster Dawood Ibrahim -- who was behind the March 12, 1993 blasts in Mumbai -- or the Pakistan-based terrorist group Lashkar-e- Tayiba.

A Mumbai special court is likely to deliver judgment on the 1993 blasts soon.