Finance Minister Arun Jaitley said that New Delhi’s changed policy makes it clear that "if Pakistan kills Indians, there is a cost they will pay."
The deaths mark the single worst day for India in casualties caused by cross-border firing since a ceasefire was declared by India and Pakistan in 2003.
Since September, when India carried out surgical strikes across the Line of Control in Kashmir, Pakistan has violated the ceasefire nearly 60 times. Eight Indian security troops have died since then. Hundreds of villagers have been evacuated and moved into government-run shelters. Schools have been closed to protect young children. The Border Security Force has said that in recent weeks, it has killed about 20 Pakistani soldiers taken out nearly as many Pakistani posts in retaliatory firing.
"Pakistan should know the times have changed," Mr Jaitley said, referring to the government's swiveling away from the policy of strategic restraint used by its predecessor in dealing with Islamabad.
"We have suffered enough in silence, we won't any more," he said. After Pakistani terrorists attacked an army base in Uri, leaving 19 soldiers dead, Indian troops entered Pakistan-occupied Kashmir and targeted gathering areas for terrorists who were planning to attack major Indian cities, the army had said.
Pakistan has accused India of misrepresenting cross-border firing as cross-border raids. In statements since then, Prime Minister Narendra Modi and other senior government officers have said that the army "has been given a free hand" to deal with unprovoked Pakistani aggression along the border.