Search operations were on for the second day on Wednesday around the Kakrapar Atomic Power Station (KAPS) near Surat to locate two persons, who were reportedly seen moving near the hi-security premises, police said in Surat.
Local police said they would continue the search outside the premises for any suspicious persons or objects.
"The search is on since Tuesday night. We could not do much after dark so the search operation has been resumed in the morning," Surat district (rural) Superintendent of Police BK Jha said.
Intense combing operations were carried out in the 'exclusive' zone between the KAPS outer fence and near the barrier around the plant.
The Central Industrial Security Force (CISF) had said on Tuesday night that they have called off the search operation within the plant premises.
The KAPS premises, that has two 220 MW nuclear power plants, has been searched thoroughly since Tuesday evening after a villager reported to CISF that "two suspicious looking men were moving around the high-security zone with arms".
The area was on an alert following the 'sighting' and police and CISF officials quickly swung into action.