Top official sources said the three were neutralised in a western state last Friday before they could carry out any attack in the country.
The remaining seven terrorists have also been zeroed in their hideouts and operation is on to neutralise them, the sources said.
As the operation is still ongoing, security agencies were not ready to give the details, the sources said.
The group, all suspected to be Pakistani terrorists belonging to LeT and JeM, had planned to attack the Somnath temple in Gujarat during Shivratri on March 7 besides other targets, they said.
Immediately after the intelligence input about the infiltration of the terrorists was received, the Centre had dispatched four NSG teams to Gujarat and they were put in different locations in the state.
An alert was sounded in Gujarat and all metros by central security agencies following reports about infiltration of the terrorists.
An advisory was issued to enhance security at all strategic locations, sensitive industrial sites and religious places after intelligence inputs suggested that the terrorists had entered Gujarat taking the sea route.
A similar alert was also sent to Uttar Pradesh, Andhra Pradesh, Telangana, Goa, Madhya Pradesh, Rajasthan and Chandigarh.
PTI