A 27-year-old man has been detained by the Maharashtra Anti-Terrorism Squad (ATS) for allegedly sending a terror e-mail to the CBI's Mumbai office, warning of strikes on August 13 in 10 cities, including Delhi, an ATS official said on Tuesday.

Tushar Sawant, a resident of suburban Vidyavihar, was detained on Monday night by the ATS, which handed him over to Kurla police for further investigations.

Sawant, who holds a bachelor's degree in IT and has been unemployed after he was removed from his job, seemed to be mentally imbalanced as he gave incoherent replies, the official said.

According to ATS, Sawant came up with an imaginary conclusion, apparently after factoring in the previous terror attacks, on how the strikes in 10 cities, including Mumbai and Delhi, would pan out on August 13.

The CBI office on May 23 received the mail and the Cyber Cell of the ATS took over the investigation, the official said.