AMNA NAWAZ: Welcome to the "News Hour."

Ukraine is reeling tonight after one of the deadliest Russian strikes since the full-scale war began more than 2.5 years ago.

Authorities say two missiles hit a military academy and a hospital in the central eastern town of Poltava today, killing at least 50 people and injuring hundreds more.

Nick Schifrin has our report.

NICK SCHIFRIN: Hundreds of miles from the front line, Russia's ballistic missiles struck so quickly, Ukrainian cadets had no time to search for safety, a military school building and a nearby hospital both destroyed and nearby homes damaged.

Violence has shattered this and every Ukrainian city and residents long ago forgot what it feels like to be safe.

Oleksandr cleaned up his broken window.

OLEKSANDR, Poltava, Ukraine Resident (through translator): There were two powerful explosions, one after the other.

Everything flew out of the cupboard.

Everything was covered in glass.

NICK SCHIFRIN: And a nearby school dusted itself off despite the danger, said 12-year-old Alisa Shtybal.

ALISA SHTYBAL, Poltava, Ukraine Resident (through translator): It was scary, fear, panic.

I don't know how to describe it.

I was worried for my parents and my sister, for my loved ones.

NICK SCHIFRIN: Once again, Ukrainian President Volodymyr Zelenskyy argued the attack should unshackle U.S. restrictions on long-range American weapons.

VOLODYMYR ZELENSKYY, Ukrainian President (through translator): Air defense systems and missiles are needed in Ukraine, not in a warehouse somewhere.

Long-range strikes that can defend against Russian terror are needed now, not sometime later.

Every day of delay, unfortunately, means more lives lost.

NICK SCHIFRIN: And there were more lives lost early today in Zaporizhzhia.

Police pulled out the bodies of victims of a Russian strike on a hotel, by daylight, among the dead, a woman and her 8-year-old son.

Zaporizhzhia is home to Europe's largest nuclear power plant, occupied by Russia since the war's first days.

Yesterday, the plant's external power source was hit with artillery.

In Ukraine, International Atomic Energy Agency head Rafael Grossi warned that could lead to the plant losing the power it needs to cool its reactor.

RAFAEL GROSSI, Director General, IAEA: I have very often characterized it as very fragile with a certain -- for some days, we have some stability and then, the next day, there is an event, an issue, a drone impact.

The situation is very serious indeed.

NICK SCHIFRIN: But, today, the war's architect was given an honor guard by a country that is legally obligated to arrest him.

Russian President Vladimir Putin visited Mongolia, a member of the International Criminal Court that has demanded Putin's arrest.

Mongolia has built relationships with the West since it transitioned to democracy in the 90s, but its economy still depends on Russia and the leaders announced today their ties would be strengthened.

VLADIMIR PUTIN, Russian President (through translator): Relations with Mongolia are among the priorities of our foreign policy in Asia and have been raised to a high level of comprehensive strategic partnership.

NICK SCHIFRIN: A small voice of dissent that demanded Mongolia execute the ICC warrant was quickly silenced when police arrested pro-Ukrainian protesters.

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