Leaders of outfits like Sri Ram Sena and Rashtriya Hindu Sena are under the scanner. "We are keeping a close watch on their activities,' the additional director general of police-law and order, R Infant told PTI in Bengaluru.

"We have taken all preventive measures today and tomorrow. Patrolling has been enhanced. Additional forces have been deployed at all sensitive locations." Infant added.

Official sources said the state government had issued instructions to police to deal sternly with the trouble-makers.

The Sri Ram Sena was first involved in an attack on women at a pub in Mangalore last month. Unfazed by the nationwide condemnation, its leader Pramod Muthalik [Images] issued threats to disrupt Valentine's day celebrations and warned that couples dating on the day would be married off by its activists.

Increasing incidents of moral policing took a turn for the worse two days ago with a teenaged girl committing suicide after she was accosted by a group of people and dragged to a police station along with her male friend.

Last night, Karnataka Governor Rameshwar Thakur had summoned Chief Minister B S Yeddyurappa [Images], apparently to seek details about the measures taken to ensure a trouble-free Valentine's day.

Union Home Minister P Chidambaram had asked the chief minister to take "preventive and punitive" action to ensure law and order in Karnataka.

Muthalik, whose threats evoked protests and criticisms, stated that his activists would educate youngsters on Hindu culture. Countering the Sena's threats, several organisations have come forward to offer protection to couples celebrating Valentine's day.