Kerala police have beefed up security in Thiruvananthapuram and issued directions to the district police chiefs to ensure law and order after the radical Islamic outfit Popular Front of India (PFI) called for a state-wide hartal on Friday.

The dawn-to-dusk hartal was called by the PFI to protest against the raids in the offices and residences of its leaders and their subsequent arrests on Thursday by the NIA and other agencies for allegedly supporting terror activities in the country.

A statement issued by the police said stern action will be taken against those who violate the law.

"All the policemen in the state will be deployed for the maintenance of law and order, " the statement said.

Meanwhile, the state-run KSRTC has informed that it will operate as usual.

The transport corporation said special services to hospitals, airports, and railway stations will be arranged if necessary and will also seek police protection if needed. ?

PFI on Thursday had said a hartal will be observed in the state on September 23 "against the RSS-controlled fascist government's attempt to silence dissenting voices using the central agencies."?

The hartal would be held from 6 AM to 6 PM, A Abdul Sathar, state general secretary, PFI, had said in the statement.

On Thursday, PFI workers had taken out marches to the places where raids were carried out and raised slogans against the Centre and its investigating agencies.

However, central forces were already deployed in all such places as part of strengthening security.

Multi-agency teams spearheaded by the NIA had arrested 106 functionaries of the PFI on Thursday in nearly simultaneous raids at 93 locations in 15 states for allegedly supporting terror activities in the country.

Kerala, where PFI has some strong pockets accounted for the maximum number of 22 arrests, officials said.?

PFI state president C P Mohammed Basheer, national chairman O M A Salam, national secretary Nasaruddin Elamaram, former chairman E Abubacker, and others were among those arrested.