In Kyiv, emergency crews were dispatched to extinguish fires caused by falling debris. The Kyiv regional military administration said it was working to clear at least six locations around the capital, including a major roadway.

Kseniia Khyzhniak, 35, had been using her day off work to catch up on a TV series when the sirens sent her racing to her children’s school.

“I’m looking at the sky, and the air defense rocket is flying there,” Ms. Khyzhniak said. There was one bang, and then another as her two young children ran to meet her and they raced to the shelter, holding hands, she said.

“Hurry up!” Ukrainians standing at the entrance yelled, waving them in, she said.

Oleksandr, 40, a technology worker who declined to provide his last name, said he, too, had found himself heading for shelter — even if he was not really sure what the point was.

“Getting hit by the car and dying is more probable in Kyiv at the moment than dying of shelling, mathematically,” he said. “But I can’t order my body how to react, you know?”