Security in the country's financial capital was heightened on Monday even as investigators continued to probe the origin of a threatening email sent ahead of the serial blasts in Ahmedabad on July 26.
Police presence was high at strategic installations, railway stations and places of religious significance in the city following the serial blasts in Bangalore and Ahmedabad.
Investigations continued today into the origin of a threatening e-mail sent to some news channels ahead of the blasts that rocked Ahmedabad.
Anti-Terrorism Squad (ATS) yesterday had raided the residence of an American national in Sanpada at Navi Mumbai in connection with the email.
A technical team is presently assisting the police in their investigations in the matter, an ATS official said.