Indian Prime Minister Narendra Modi vowed on Thursday to pursue, track and punish terrorists and their backers in a strong reaction to a deadly militant attack on tourists in Kashmir, where police have identified two of the gunmen as Pakistani.

The Pakistani government announced a series of sweeping retaliatory measures a day after India took aim at its neighbor and archnemesis.

Pakistan called India's actions “irresponsible" and canceled visas for Indian nationals, suspended all trade with India and closed its airspace to Indian aircraft.