India has imposed an immediate ban on imports from or via Pakistan, citing national security concerns following a deadly militant attack in Kashmir that left 26 tourists dead.

The Directorate General of Foreign Trade announced the move as tensions escalate between the two nuclear-armed neighbors. India blames Pakistan for the attack, a claim Islamabad denies.

In response, Pakistan has halted border trade, closed its airspace to Indian flights, expelled diplomats, and warned that interference with river water flows under an existing treaty would be seen as an act of war.

Trade ties between the two countries have already been strained in recent years.