Ukraine’s state-run railway company Ukrzaliznytsya said there were no immediate reports of casualties. It added that the building suffered minor damage but trains are still operating.
A Ukrainian interior ministry adviser said the blast was caused by wreckage from a downed Russian cruise missile, not a direct rocket strike.
It comes on the seventh day of Vladimir Putin’s assault on Ukraine.
The country’s second biggest city, Kharkiv, has suffered heavy bombardment but Ukrainians denied Russia’s claim that its forces had taken the Black Sea port of Kherson.
Meanhile, Russia is increasingly isolated on the international stage after the United Nations General Assembly overwhelmingly voted to demand an immediate end to the invasion.
Some 141 nations backed the motion, with only five – including alleged co-aggressor Belarus – opposing it.
Boris Johnson today said Putin’s forces are committing war crimes as troops step up the bombardment of Ukraine’s cities.
READ MORE: Horror as Putin’s troops open fire on unarmed Ukrainians
At Prime Minister’s Questions, Mr Johnson said: “Putin has gravely miscalculated; in his abhorrent assault on a sovereign nation, he has underestimated the extraordinary fortitude of the Ukrainian people and the unity and resolve of the free world in standing up to his barbarism.”
More than 2,000 civilians have died since the invasion, Ukraine’s state emergency service said, although that figure has not been independently verified.
The United Nations’ refugee agency believes around 874,000 people have fled Ukraine but that figure is soon expected to reach a million.
Mr Johnson told MPs: “What we have seen already from Vladimir Putin’s regime in the use of the munitions that they have already been dropping on innocent civilians, in my view, already fully qualifies as a war crime.”
But the Prime Minister said “the vice is tightening on the Putin regime” through the sanctions imposed by the West.