When the shelling starts, the people who remain in the devastation of Avdiivka hardly flinch. In truth, the shelling barely stops. In this ravaged town in eastern Ukraine, the thud of Russian artillery reverberates every minute or two.
“Do you hear? It’s flying,” one resident said as a rocket passed overhead. “Then there is a boom,” he added as it detonated.
As Russia wages an offensive across a broad front in eastern Ukraine, in the last few weeks it has intensified its bombardment of Avdiivka and outlying villages, near the Russian-held regional capital, Donetsk. The barrage has left Avdiivka, already battered and largely abandoned by residents after a year of war, without power, running water or intact shelter for its civilian holdouts.
Moscow’s monthslong advance has been slow: It has yet to capture any major towns. But it is also devastating, claiming casualties by the tens of thousands and reducing the places in its path to ruins.
On Monday, the Ukrainian government barred civilians from entering the town, citing safety concerns; the top official in Avdiivka, Vitaliy Barabash, called it “like a site from postapocalyptic movies.” A team of New York Times journalists visited on Monday just before the ban was announced.
Residential communities were strewn with the ruins of blasted buildings, pavement and vehicles, making streets nearly impassable by car. Schools, health clinics, shopping centers and apartment blocks had been left with gaping holes. Chunks of unexploded ordnance protruded from the streets.
The remaining residents were living in damp, candlelit basements beneath Soviet-era apartment buildings, pervaded by stifling smells, where they had set up beds, makeshift kitchens, bookshelves and small Orthodox shrines. Ukrainian police went from basement to basement, trying to persuade civilians to evacuate.
The longtime focus of the Russian offensive, Bakhmut, lies 34 miles to the northeast, and Moscow has not let up in its assault there, even as fighting escalates elsewhere along the front, officials on both sides said on Tuesday. Russian forces have fought for nine months to seize Bakhmut, advancing from three directions and recently taking control of the eastern side of the city, but Ukrainians have held fast on the western side.
“They are not giving up their attempts to surround and capture the city,” Gen. Oleksandr Syrsky, commander of Ukrainian ground forces, said on the Telegram messaging app.
Denis Pushilin, the Russian-installed leader of the Donetsk region, said on Russian state television that the Kremlin’s forces were pushing ahead, wresting control from the Ukrainians of a metals factory on the western side of Bakhmut, a claim that could not be independently verified.
The battle there has killed or wounded thousands, and officials on both sides have claimed that the carnage has served to wear down its enemy.
Britain’s Defense Ministry said in an intelligence update on Tuesday that a parallel effort to encircle and capture Avdiivka had become a high Russian priority but had “made only marginal progress at the cost of heavy losses in armored vehicles.”
The Ukrainian military’s General Staff said on Tuesday that Ukrainian forces had repelled 62 attacks in the previous 24 hours in Bakhmut, Avdiivka and Marinka, another eastern town nearby.
With more powerful Western weapons arriving and fresh troops being conscripted, Ukraine is widely expected to launch a counteroffensive soon, hoping to retake Russian-held territory. Analysts say the main push is likely to be farther west, in the Kherson and Zaporizhzhia regions.
In Zaporizhzhia, “there is a quite obvious increase in the number of troops on both sides, military equipment, etc.,” Rafael Mariano Grossi, the chief nuclear-energy watchdog for the United Nations, said in an interview on Tuesday. “Our teams are also observing and hearing and seeing more military activity, including detonations.”
Mr. Grossi is in the region and plans on Wednesday to visit the Zaporizhzhia Nuclear Power Plant, seized by Russia last year. It has been damaged repeatedly in the fighting, raising fears of an incident that could cause a major radiation release. Mr. Grossi is trying to negotiate an agreement to make the plant and its surroundings a demilitarized zone.
Russia has repeatedly hinted at another kind of nuclear danger: the use of nuclear weapons. On Sunday, Mr. Putin said Russia could soon station such weapons in Belarus, its ally, which borders Ukraine to the north. The government of Belarus said on Tuesday that it would be open to Russian tactical nuclear weapons on its soil.
Western analysts say such talk is most likely bluster and note that Russia already has the capacity for nuclear strikes in Ukraine, but the threats keep the topic on Ukrainian and Western minds.
The United States has informed Russia that it will no longer share data on American nuclear forces as required under the New START nuclear arms-control treaty, Biden administration officials said on Tuesday. Mr. Putin said last month that Russia was suspending its participation in the treaty, and it had already blocked American inspections of its arsenal under the treaty.
Despite the suffering and risks, neither Moscow nor Kyiv has shown serious interest in ending the war, except on terms the other side calls unacceptable. President Vladimir V. Putin of Russia has said that his top priority is conquest of the eastern Donetsk and Luhansk regions, which his forces mostly control. His government claims to have annexed to Russia those two provinces, and also Zaporizhzhia and Kherson, though it does not hold the entirety of any of the four.
President Volodymyr Zelensky of Ukraine has said his country will accept nothing less than the Russians either withdrawing or being expelled from all Ukrainian territory. Stopping the fighting before that, Ukrainian and American officials say, would only cement into place Russia’s illegal gains.
Secretary of State Antony J. Blinken reiterated that position on Tuesday in a thinly veiled swipe at a proposal by China, Russia’s most important ally, that includes a cease-fire. Though he did not mention China by name, Mr. Blinken warned against any plans that would simply give Russia room “to rest and refit and then reattack,” he told foreign ministers in a video meeting of foreign ministers from around the world.
“What seems to be appealing on the surface — who wouldn’t want the guns to be silent? — can also be a very cynical trap that we have to be very, very careful of,” he added.
Where the guns are loudest, near the front lines across eastern and southern Ukraine, most residents fled long ago, but some remain. That is evident in Avdiivka, which lies just outside Donetsk city, controlled by Russians since the Kremlin’s separatist proxy forces seized it in 2014.
Out of 30,000 people who lived in Avdiivka before the full-scale Russian invasion, Ukrainians say only hundreds remain. They mostly stay underground, where it is safer. One retiree said she hadn’t been outside for five months.
People have stayed behind for various reasons. Some say they are too ill, others too attached to their prewar lives. Most are middle-aged and older.
“I’ve been living here for 43 years. How can I leave Avdiivka?” said one older resident, Polina, who emerged from a basement to drop off cat food for a neighbor and check on damage to her apartment. Like others interviewed for this article, she gave only her first name, fearing for her safety.
“At my old age, I don’t want to hop around to different apartments somewhere else,” she added.
Nearby, a building was still smoking after a recent rocket strike.
Still others say they are too poor to move. Some appear psychologically paralyzed after months of shelling. Many simply sit on their beds and stare blankly.
And in a region with strong ties to Russia, loyalties are sometimes divided. Two older residents appeared to support Russia and blamed both sides of the war for shelling their community.
Many residents knew a pair of police officers who visited on Monday, from previous visits, and were used to their attempts to persuade them to leave.
One mother, Natalya, agreed to be evacuated with her 3-year-old daughter, Marina. She was distraught as she packed their few belongings into plastic bags and said she had no money to start a new life.
But most of those approached rebuffed the officers, then scuttled back down to their basements and slammed the doors.
Reporting was contributed by Matthew Mpoke Bigg from Kyiv, Edward Wong from Washington and Enjoli Liston from London.