GEOFF BENNETT: Welcome to the "News Hour."

Tonight, Pakistan is vowing to avenge Indian missile strikes that Pakistan says killed more than 30 people.

AMNA NAWAZ: India says it targeted terrorist infrastructure in retaliation for an attack last month in Indian-administered Kashmir.

President Trump today called for the violence to end, but cross-border fire between the countries continues and there's worry in both countries of escalation.

Nick Schifrin begins our coverage.

NICK SCHIFRIN: This morning, in the mountains of Pakistan-administered Kashmir, a mosque shattered into a shell, 350 miles to the south, another mosque gutted, its dome ripped off.

Pakistani officials say an Indian attack here killed 13.

MOHAMMAD ZUBAIR, Pakistan Resident (through translator): This is a cowardly action by India.

There are certain rules in war.

Places of worship, hospitals and educational institutions are not attacked.

Women and children are not harmed.

NICK SCHIFRIN: Last night's strikes the most widespread aerial attack by India on Pakistan in half-a-century.

India says it targeted nine sites used by Pakistani militant groups, most of the targets within Pakistan-administered Kashmir, but some missiles hit in Pakistan's Punjab province, Pakistan's heartland, where India has long accused Pakistan of hosting terrorist training.

India calls it revenge for the death of more than two dozen mostly Hindu tourists in April, the deadliest attack on civilians in Indian-administered Kashmir in decades.

And India today said its attacks were proportionate, not designed to escalate, and preemptive.

VIKRAM MISRI, Indian Foreign Secretary: Our intelligence monitoring of Pakistan-based terrorist modules indicated that further attacks against India were impending.

There was thus a compulsion both to deter and to preempt.

NICK SCHIFRIN: But India appeared to suffer significant losses.

Pakistan said it shot down five Indian fighter jets and drones.

India hasn't commented, but local media filmed crash plane debris.

And Pakistan is threatening a further response.

This morning, its National Security Committee warned: "Pakistan reserves the right to respond in self-defense at a time, place and manner of its choosing to avenge the loss of innocent Pakistani lives and blatant violation of its sovereignty."

Pakistani Prime Minister Shehbaz Sharif: SHEHBAZ SHARIF, Pakistani Prime Minister (through translator): We vow that every drop of blood of our martyrs will be accounted for.

NICK SCHIFRIN: Meanwhile, both sides shelled across the de facto border in Kashmir.

And India says Pakistani artillery killed at least 12 and wounded more than 50, including children.

Today, President Trump made it clear the U.S. wanted last night's round to be the end.

DONALD TRUMP, President of the United States: I want to see them work it out.

I want to see them stop.

And, hopefully, they can stop now.

They have got to tit for tat.

So, hopefully, they can stop now.

NICK SCHIFRIN: But, tonight, there's an expectation of escalation.

This is a drill that Indian authorities held today to prepare civilians for more attacks.

For the "PBS News Hour," I'm Nick Schifrin.