Bhopal, Sep 27 : Madhya Pradesh ATS on Tuesday detained 21 members from eight districts of the state over links with Popular Front of India (PFI). An official told IANS that raids were carried out in the wee hours in eight districts, including three big cities - Bhopal, Indore and Ujjain. "Among those detained are workers associated with PFI. Further operation is underway," a senior police official said. In Bhopal, the ATS conducted raids at SDPI's (Social Democratic Party of India) office located at Shahjahanabad area late on Monday and detained one suspect for interrogation. Persons associated with SDPI are suspected to have been funding PFI, and the ATS claimed to have recovered some documents related with the same. In the second round, the ATS' operation began on the basis of inputs of the National Investigation Agency (NIA). Notably, last Thursday, the ATS had conducted raids in Indore and Ujjain during which four PFI members were arrested. /IANS