Taking serious note of threat of 'fidayeen' attacks on key installations, the government has completely revamped security at all nuclear establishments in the country, National Security Advisor M K Narayanan said on Tuesday.

The security arrangements put in place are 'adequate' to meet the threat, he told reporters after a day-long meeting of chief ministers on internal security, which was chaired by Prime Minister Manmohan Singh [Images].

Narayanan was asked about the concerns expressed by Dr Singh during the conference on increasing activities of 'externally inspired and directed terrorist outfits' in the country.

The prime minister had said that intelligence agencies had warned of further intensification of violent activities with the possibility of more 'fidayeen' attacks that could target nuclear establishments.

"We have completely revamped security for all nuclear establishments," Narayanan said.

Home Minister Shivraj Patil also warned about the nefarious designs of certain elements wanting to create communal disturbance in the country.

Patil said the conference was not aimed at finding faults but to evolve ways for closer cooperation between the Centre and the states to tackle security threats and improve intelligence-gathering mechanisms.