Key installations in the oil and natural gas sector, defence, communications and IT are also equally vulnerable, he said while inaugurating a three-day conference of state police chiefs in New Delhi.
"In view of the recent Indo-US agreement on civil nuclear energy cooperation, our atomic power plants have become highly vulnerable," Patil said.
"Some Lashkar-e-Tayiba terrorist operatives are being trained specifically for sabotage of oil installations. There are plans to occupy some uninhabited islands and use them as bases for launching operations on the Indian coast."
The country's critical infrastructure faced "serious" threats from terrorists, he added.
Patil said there were reports to indicate that some multi-purpose projects in the country continued to be targets of terrorist groups.
The country's coastal boundary was also under constant threat from terrorists, he said.
Patil said there were reports to indicate that some of the country's multi-purpose projects and shipyards continue to be targets of terrorists groups.
"In view of the assessed threat, government has asked the littoral states to establish marine police stations for which the home ministry has sanctioned Rs 400 crore for establishing infrastructure and purchasing boats.
"Training of these marine policemen has commenced with the help of the Coast Guard and efforts are afoot to integrate command and control among the police," he said.
Referring to Jammu and Kashmir, Patil said the increase in incidences of infiltration and demonstrative acts of violence by militants "intent on a well callibrated agenda" had "viatiated the environment" there.
"Targeting by terrorists of vulnerable groups like tourists, non-state subjects and minorities including a high-profile suicide attack. were clearly attempts by terrorists to thwart the political processes aimed at reconciliation," he said.
Patil said the "...penchant of various terrorist outfits operating in Jammu and Kashmir to indulge in wanton violence means that the safety of soft targets will continue to remain a priority concern for security forces."
To allow the political process to take the desired direction, he said, "It is imperative that the state witnesses perceptibly lower levels of violence, which requires a strong will and determination to sustain the anti-militancy effort."
Referring to the northeast, the home minister said while the overall situation had shown signs of improvement, the continuing violence in Manipur and a surge in depredations by the ULFA in Assam "are worrying indicators".
Ceasefires with several underground groups had been achieved, but the government cannot countenance the willful use of violence by militant groups against the common man while talking about peace, Patil said.
"These groups must realise that the people have clearly rejected wanton violence and showed a clear desire for peace and stability that alone can guarantee development," he said.
Cooperation between police forces and other security agencies in the northeast, he said, was "absolutely vital" as there were close inter-linkages among militant groups in the region in areas like arms procurement and training.
Describing Naxalism as a serious threat to internal security, Patil said Naxalites had carried out "some chilling and dastardly actions" in the past year that pointed to "critical gaps in collection of tactical intelligence."
Noting that Naxalism feeds on widespread socio-economic, political and regional inequities, he said, "No grievance, whether real or imaginary, can justify resort to such terror tactics and violence in any civilised society."
The recent seizure of rocket shells and launchers in Andhra Pradesh showed that the Naxalites are determined to acquire a sophisticated arsenal to improve their military might, he said while asking Maoist groups to abjure violence and to contribute to developmental efforts rather than obstructing the same.
Patil also emphasised the pressing need to gear up the intelligence gathering machinery right down to the level of police stations.
"We have circulated a detailed model structure for the state special branch which includes not only a qualitative restructuring of the existing set-ups but also professional upgradation of the staff posted there," he said.
Referring to the Police Mission and police reforms being pursued by the government, Patil said, "We will have to create a police service that not only ensures the rule of law but also is viewed as fair, efficient and honest; and is able to meet the democratic aspirations of the people."
Patil presented Indian Police Medals to 17 officials of the Intelligence Bureau. Lauding the role of the IB, he said, "I am aware that the good work done by its unseen and unsung heroes goes largely unacknowledged due to the secretive nature of their functioning."
Earlier, in his welcome address, Intelligence Bureau chief E S L Narisimhan, who is the chairman of the conference, advocated the need for a strong security response against militant groups like the Jaish-e-Mohammed and Lashkar.
"The enemies of the country want to project the militancy in the country as indigenous and for this purpose, they have been recruiting some local youth for arms training," he said.
"Though the number is very very low, there is no room for any complacency."
About the northeast, he said the situation there was largely peaceful but the continued sheltering of militant outfits in Myanmar and Bangladesh could complicate matters.