Explosions were also reported in other cities across Ukraine including Dnipro, Kryvyi Rih, Sloviansk and Kramatorsk, Zelenskyy said. “More than 40 missiles of different types were used,” he said in a Telegram post.

In total, about 20 people are believed to have died and about fifty were wounded across Ukraine as the result of Monday morning’s attack, Ihor Klimenko, the country’s interior minister, said.

Kryvyi Rih mayor Oleksandr Vilkul said 10 people died in his city alone. Another 41 were injured.

Yermak, the head of Zelenskyy’s office, earlier said the attacks occurred at a time when many people were in the city’s streets.

The attack came on the eve of a three-day NATO summit in Washington, which will look at how to reassure Ukraine of the alliance’s unwavering support and offer Ukrainians hope that their country can come through Europe’s biggest conflict since World War II.