HULIAIPOLE, Ukraine — The shelling begins in earnest a little before midnight, well after the sky has turned oily black, the cell towers have powered down and the stray dogs bark into the night.

There is no electricity or running water in Huliaipole. There is just darkness and long minutes of silence when the ticking of battery-powered wall clocks or the grating of open gates in the cold wind are anxiously scrutinized until the next explosion thuds somewhere nearby, rattling windows. And bones.

And then it happens again. And again. A high-pitched screech and then a boom. Sometimes the shells get closer. Or farther away. Maybe, for a few hours, they stop altogether. But it’s been the same routine for almost a month in this town along the front lines in eastern Ukraine, with each night bringing the same question: Where will the next one land?

“It’s like living in a horror movie,” said Ludmila Ivchenko, 64, between tears, bundled in her winter parka on Monday. She rocked back and forth, sitting beside the flame of an oil candle deep in the basement of the town’s hospital where she and her neighbors now live.

As Ukrainian cities such as Kharkiv and Mariupol are being torn apart by intense bombardments, cruise missile strikes and infantry advances, Huliaipole, a town once home to about 13,000 people, is dying a much slower death.

The town, about 90 miles northwest of Mariupol and on the edge of the Donbas region, would likely be in the path of any future Russian offensives in the east, where the Russian defense ministry said Wednesday it would focus its operations.

Strategically situated at the intersection of important roads bisecting the country, Huliaipole is surrounded by a half-moon of Russian and separatist forces that are perfectly content with shelling the town instead of taking it, likely because they don’t have the resources yet to do so, military analysts say.

The residents of the shrinking enclave — now down to about 2,000 people — are caught in the middle of dueling artillery battles between Ukrainian and Russian forces as homes, apartments, markets, restaurants and health clinics are slowly destroyed, and people are forced to flee, live underground or die.

To the people still there, Huliaipole’s war began on March 2: the day the power went out. The water supply followed.

Bracketed by rolling wheat and sunflower fields and bisected by the Haichur River, Huliaipole looks and feels like a Soviet-era staple: modest homes and low-slung apartment buildings with spacious tree-lined streets, perfect for an afternoon bicycle ride in another time.

On March 5, Russian forces briefly entered the town before being pushed back. The collection of vacant half-destroyed stalls where people once sold vegetables and other goods is a strange reminder that this was once a real town. Now there is a patchwork of empty buildings with broken windows and missing roofs inhabited more by stray dogs than people.

Around a dozen civilians have died from the fighting, local officials said, a number that includes people who have suffered heart attacks during the siege.

“There is shelling every day,” said Tetiana Plysenko, 61, a teacher in Huliaipole.

Every morning, people emerge from their homes and shelters to assess the damages and call their neighbors to make sure they are still alive. Rumors are rampant, as is misinformation. One rumor is that a local was caught helping mark targets for the Russian military and was subsequently hanged. No one can really say if it was true, or not.

“We still can’t understand that this has happened to us. We think that we’ll go out tomorrow and everything will be as before,” Ms. Ivchenko said from her basement shelter. “But there is no way to go back.”

For now, Huliaipole is patrolled by a small contingent of Ukrainian territorial defense soldiers. The job of evacuating people, and bringing in humanitarian aid, falls to the 10 or so people on the Town Council. They have repurposed the town’s school buses to bring in food and water and take out people desperate to escape the shelling.

Sergiy Brovko, 57, a short, wiry bus driver whose crow’s feet wrap around the side of his head, had been ferrying children to school for less than a year before the war reached the town. Now Mr. Brovko drives his aging Isuzu bus to the city of Zaporizhzhya and loads up humanitarian aid: boxes of bread, cans of goulash and water. Then, he makes the hourslong trek back to Huliaipole.

“I could never have imagined this,” Mr. Brovko said on Monday, as he headed toward Huliaipole on his seventh run there since the war began. He maneuvered his bus over the potholed roads common in Ukraine’s more rural reaches, downshifting to almost a standstill to navigate the larger craters left by overuse and disrepair.

“Not even in my nightmares.”

The road from Zaporizhzhya into Huliaipole begins somewhat normally, aside from the military checkpoints and cement road barriers. But the posters throughout the city are a peculiar mix of things, signaling what life had been like in the city not long ago and what now lies beyond Zaporizhzhya’s gates: Between concert announcements and McDonald’s arches are billboards informing passers-by which part of a Russian tank to target with a Molotov cocktail.

As Mr. Brovko gets closer to Huliaipole, the traffic thins out. Small towns along the road seem eerily closed, almost like abandoned movie sets. Ukrainian checkpoints are manned by young and old men. Newly dug trench lines zigzag away from the road, fortified by freshly cut logs and machine gun positions. By the time Huliaipole comes into view, Mr. Brovko has passed several recently planted signs that declare: MINES.

“I evacuated my parents yesterday,” he explained, pointing out that a house on their street had recently been hit by artillery fire. Just days ago, he said, he had to wait to enter Huliaipole, his bus loaded with nearly 500 pounds of potatoes, until the Russians finished shelling it.

On Monday night, Mr. Brovko parked his bus on the outskirts of town, riding his bicycle back to his father-in-law’s house, where he would spend the night before loading his bus with evacuees the next morning. His neighbors had fled a week earlier, leaving their puppy behind, so the school bus driver-turned-evacuee-transporter-turned-dog sitter fed the animal some bread before setting his alarm for 5:45 a.m. and going to sleep.

Tuesday’s sunrise was bitterly cold. The shelling had stopped around four in the morning, rolling off into the distance to some other frontline hot spot. Boxes of milk, water, bread and other goods were unloaded off Mr. Brovko’s bus to a collection of volunteers, before he drove a few blocks to pick up the day’s tranche of evacuees.

The 40 or so people would all be driven to Zaporizhzhya, where they would register as displaced people. Some would be housed in school dormitories and gymnasiums or with friends and family. Others would leave the country. More than four million people have fled Ukraine since Russia invaded on Feb. 24 and 6.5 million have been internally displaced, according to the United Nations refugee agency.

Of the roughly dozen people who boarded Mr. Brovko’s school bus, mostly women and children, their reasons for leaving Huliaipole were similar: The shelling was getting worse, and coming closer. It was too much.

They quietly stepped onto the yellow school bus on Tuesday, some in tears. One woman said goodbye to her small toffee-colored dog, Asya, as evacuees are not allowed to take pets with them. Another woman, Valia, 60, was taking her granddaughter to reunite with the girl’s father before leaving southern Ukraine. When the granddaughter asked where they would live, the grandmother told a lie to reassure her.

“To Dubai,” said Valia, who declined to give her last name. “The sea is turquoise there.”

Not long after the buses left Huliaipole, the shelling resumed and lasted throughout the day, said Kostiantyn Kopyl, 45, a surgeon in the hospital and a member of the local territorial defense unit. Ukrainian forces fired back at night, and those remaining in the town did what they did every night: listened and waited for the next explosion.

“Everybody’s alive,” he reported.