CHENNAI: The Tamil Nadu police arrested four alleged extremists yesterday, a day after they picked up one person, and recovered from them explosive devices and bomb-making components.

The men are believed to have provided logistical support to those behind the terror bombings in Bangalore and Ahmedabad.

The four men had also hatched a plot to set off at least 11 explosions on Independence Day, Aug. 15, the police said. An unspecified number of people have been detained on suspicion and those found harmless were being let off, police sources said.

While three of the suspects were picked up in Chennai, the fourth was apprehended in Tirunelveli, 600 km south of here, an official press statement said. A vast array of timers, improvised explosive devices and bomb components seized from two suspects — Sheikh Abdul Ghaffoor and Mohammad Anwar Badshah — in Tirunelveli were allegedly meant to be used in blasts in 11 places in the state.