The police have been given instructions to keep strict vigil on the activities of Maoists in Kerala [Images], Home Minister Kodiyeri Balakrishnan has said.

Talking to reporters, he said the police had received reports that certain groups were trying to spread Maoist ideology among youth.

"The police has been asked to keenly observe their movements," he said.

He said there were no "pockets of influence" for Maoists in Kerala but reports indicated that they were now indulging in secret ideological campaign.

As the state had vibrant mainstream politics, it was very difficult for any extremist outfit to find roots here, he said.

To a question, he said there were no reports of any activity by Hizbul Mujahideen in the state.

He said some individual human rights activists were having links with extremist elements and were "helping" them under the cover of rights activism.