India is vowing to hunt down terrorists "to the ends of the earth" Thursday as tensions with Pakistan escalate in the wake of a shooting in India's Kashmir region that left 26 people dead.

Prime Minister Narendra Modi said at a public rally that "India will identify, track and punish every terrorist, their handlers and their backers." 

"We will pursue them to the ends of the earth," he reportedly added. 

Tuesday's attack was the worst assault in years targeting civilians in the restive region that has seen an anti-India rebellion for more than three decades. Gunmen opened fire on mostly tourists who were visiting a popular scenic meadow, killing 26 and injuring 17, according to Reuters. 

INDIA DOWNGRADES TIES WITH PAKISTAN AFTER ATTACK ON KASHMIR TOURISTS 

The Indian government did not publicly produce any evidence connecting the attack to its neighbor, but said it had "cross-border" links to Pakistan. However, Pakistan denied any connection to the attack, which was claimed by a militant group that called itself the Kashmir Resistance. 

Indian authorities said Thursday that all visas issued to Pakistani nationals will be revoked with effect from Sunday, adding that all Pakistanis currently in India must leave before their visas expire based on the revised timeline. The country also announced other measures, including cutting the number of diplomatic staff and closing the only functional land border crossing between the countries. 

TRUMP EXTENDS ‘DEEPEST SYMPATHIES’ AFTER GUNMEN KILL 20 IN INDIA’S KASHMIR REGION 

In response, Pakistan closed its airspace for all Indian-owned or Indian-operated airlines and suspended all trade with India including to and from any third country. 

Pakistan’s National Security Committee also condemned India’s "belligerent measures." It said that while Pakistan remained committed to peace, it would never allow anyone to "transgress its sovereignty, security, dignity and inalienable rights." 

President Donald Trump extended his "deepest sympathies" on Tuesday following the attack. 

"Deeply disturbing news out of Kashmir," Trump wrote on his TRUTH Social account. "The United States stands strong with India against Terrorism. We pray for the souls of those lost, and for the recovery of the injured. Prime Minister Modi, and the incredible people of India, have our full support and deepest sympathies. Our hearts are with you all!"  

Fox News Digital’s Danielle Wallace and the Associated Press contributed to this report.