SRINAGAR, India — India and Pakistan canceled visas for their nationals to each other’s countries and Islamabad warned New Delhi for suspending a water-sharing treaty Thursday.

The moves came after India blamed Pakistan for a deadly attack by gunmen that killed 26 people in disputed Kashmir.

India said 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, closing the only functional land border crossing between the countries and suspending a crucial water-sharing agreement.

In retaliation, 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.

Tuesday’s attack in Kashmir was the worst assault in years, targeting civilians in the restive region that has seen an anti-India rebellion for more than three decades.

The incident shocked and outraged Indians, prompting calls for action against their country’s archenemy, Pakistan. The Indian government said the attack had “cross-border” links to Pakistan, without publicly producing any evidence to support that claim. Pakistan has denied any connection to the attack, which was claimed by a previously unknown militant group calling itself the Kashmir Resistance.

Pakistan’s National Security Committee condemned India’s “belligerent measures.”

Government ministers on both sides have hinted that the dispute could escalate to military action. Pakistan’s Foreign Minister Ishaq Dar told local Dunya News TV channel that “any kinetic step by India will see a tit-for-tat kinetic response.”

Indian Defense Minister Rajnath Singh pledged Wednesday to “not only trace those who perpetrated the attack but also trace those who conspired to commit this nefarious act on our soil,” and hinted at the possibility of military strikes.

India and Pakistan each administer a part of Kashmir, but both claim the territory in its entirety. New Delhi describes all militancy in Kashmir as Pakistan-backed terrorism. Pakistan denies this, and many Muslim Kashmiris consider the militants to be part of a home-grown freedom struggle.

The killings have put pressure on Indian Prime Minister Narendra Modi’s Hindu nationalist government to respond aggressively.

“India will identify, track and punish every terrorist, their handlers and their backers,” Modi told a rally Thursday. “We will pursue them to the ends of the earth.”

His government announced a series of diplomatic actions.

India’s Foreign Secretary Vikram Misri announced Wednesday that a number of Pakistani diplomats were asked to leave New Delhi and Indian diplomats were recalled from Pakistan.

Diplomatic missions in both countries will reduce their staff from 55 to 30 as of May 1.