Police Saturday claimed to have "almost fixed" the author of the e-mail that threatened to blow up Parliament as they detained 12 people, including a professor and two students of a college and a sympathiser of militant outfit Al-Umma, in Tirunelveli district.

• Parliament bomb threat: Five secured for questioning

"We think we have almost fixed the author of the e-mail, but we have to do a lot of work before we confirm it," a senior police official involved in the investigation said.

A Tamil lecturer Sindha Sait, two students of computer science Abbas and Gnaniar and a non-teaching employee of the Sathakatullah Abbas College, besides Selvin and Muthuraj, owners of two browsing centres were in police custody, sources said.

Four women, a mobile phone shop owner and a sympathiser of militant outfit Al-Umma were also under detention. All those detained were being interrogated by police along with officials from Inteeligence Bureau  and Reserch & Analysis Wing, they said.

Police officials were also closely monitoring some e-mail centres in Salem and Erode on the suspicion that some militants might be staying in either of the towns.

Armed policemen have been deployed around the two e-mail centres from where the e-mail threat had orginated and a team of cyber crime experts are browsing through the volume of e-mail messages sent from the centres.

The messages sent from various other centres in the same town were also being analysed to fix the culprit. Police had also searched the customer log book at both the cybercafes and also questioned a few customers in connection with the case.