As the capital reeled from Saturday's serial blasts, intelligence agencies were seeking to figure out which could the next possible target of the terrorists and their estimate is that Mumbai, India's financial capital, could be in the terror crosshair.

"We don't want to spread any alarm, but we need to make every calculation to try and be a step ahead of the terrorists," said a source familiar with the investigations, adding, "Mumbai could be the next target." This estimate is derived from several factors, the chief among them being the ease with which Abdus Subhan, the techie-bomber from Mumbai, who is suspected by security agencies to be among the top plotters of attacks in Delhi, Ahmedabad and Jaipur, can find sanctuaries in the city.

The email sent by Indian Mujahideen, which sources say virtually carries the signature of Abdus Subhan, is from Mumbai and this has again highlighted his success in securing safe houses in the city despite the massive manhunt for him. This was third time when Subhan, who has been evading police since his name figured in the Mumbai train attacks, defied police surveillance to send a terror mail by abusing an unsecured Wi-Fi connection. If his audacious moves are a serious concern by themself, what's adding to the investigators' worry is the strong grudges he appears to nurse against Mumbai and certain city personalities.

While Subhan is driven by a strong animus against the city, intelligence agencies also suspect that anti-India elements belonging to Lashkar may like to hit the financial capital as part of the campaign against India. The links between IM and Lashkar are deep and have found reflection in the praise of two "legendary" Lakskar jehadis, Sayeed Ahmad and Shah Ismail in the IM email.

Subhan's anger against Bal Thackeray came off strongly in the email. "Bal Thackarey is free, Ijaz Pathan is dead, Tiger Memon is still running away, and Shiv Sena continues to spread its terror on the street of Mumbai and Maharashtra," he wrote in the email sent on May 13. Intel sources point out that in that mail Subhan vents his anger against CM Vilasrao Deshmukh, his deputy R R Patil for alleged atrocities on Muslims and threatens a repeat of the serial blasts on suburban trains.