Kannur: Three country-made bombs and a sword were seized in a raid at an under construction building and 21 alleged activists of Popular Front of India taken into custody at Narath area, police said on Tuesday.
Some PFI leaflets, an identity card and a human dummy were also recovered from the building, they said adding two persons guarding the centre fled on seeing the police.
The 21 persons arrested, all from outside Kannur and suspected to be attending a camp of the outfit, were being questioned, they said.
Meanwhile, BJP district President K Ranjith demanded a National Investigation Agency (NIA) probe into the seizure of weapons.
Claiming that Kannur has become a centre for "terror" activities, Ranjith said such centres were functioning at various places in the district.