I’ve noticed an increase in police checking in Kochi? Can they search your bag/pockets/vehicles without consent and/or warrant?

Since Christmas and new year is around the corner, the patrolling of police has increased. The media also shows police randomly stopping pedestrians and vehicles to check their bags, belongings and their vehicles for any drugs and other illegal substances. They are even carrying drug detecting devices. But is this all legal? Can they do these searches without a proper warrant, or even the consent of the person? I’ve also heard about some zones in kochi, where they do not need any permission or warrant to do such searches. Is that true, and if yes, which all are these zones in Kochi?