Their Sons Went Missing Fighting for Ukraine. They Want Answers.

Hundreds of women draped in Ukrainian flags, carrying banners and balloons, chanted on the street around the corner from the president’s office last week.

Blocked by police officers and sandbags, they called on President Volodymyr Zelensky by name. “Zelensky! Zelensky! Zelensky! Zelensky!”

Every so often an angry tirade cut through the noise.

“Where is my brother?” shouted one woman. “Bring them back home!” a teenager screamed tearfully.

Public complaints about the conditions soldiers are suffering at the front, and the rising numbers of dead and missing, have been a phenomenon seen in Russia since its full-scale invasion of Ukraine last year. But last week’s demonstration was a rare venting on the Ukrainian side, from families desperate for news of soldiers who have gone missing in action over more than 20 months of fighting.

Petro Yatsenko, a spokesman for the government’s Coordination Headquarters for the Treatment of Prisoners of War, said the body was working to provide families with information but that it had not been able to establish whether the many missing had been killed or captured. He added that Russia had demonstrated a lack of cooperation about people it had detained.

“We understand that people need to voice their frustration,” he said in a telephone interview Wednesday. “The main problem is that Russia does not provide full information, including of civilians whom they are holding illegally.”

The Russian Defense Ministry did not reply to request for comment.

Even as graveyards have steadily filled across Ukraine, there has been little overt criticism of the size of the losses or the government’s handling of the war. The public mood, bolstered by widespread volunteer work, has been volubly and sincerely united in its support of Mr. Zelensky and the armed forces.

But the pain and losses are accumulating.

The number of Ukrainians missing in the war runs to 26,000. Fifteen thousand soldiers are missing in action, the Interior Ministry said earlier this month and 11,000 civilians. Relatives of missing soldiers have become increasingly frustrated by the government’s failure to provide answers.

Some families at the Oct. 16 demonstration said they had been searching for more than a year for news of soldiers who went missing. They traveled to the capital from all over Ukraine, from the Carpathian Mountains in the west to the frontline cities in the east.

Many clutched posters and photographs of their missing soldiers, revealing their pain with a shaking hand or a wobbling voice as they wiped away tears.

One couple held a banner that read: “We are Proud of the Heroes of the 81st Brigade. We Want to Find Them and Bring Them Home.” They said their son, Vadym Safronyuk, 27, went missing in August in eastern Ukraine.

“We last heard from him when he went forward to positions on Aug. 1,” Vadym’s father, Serhiy Stepanets, said. “On Aug. 7 we were told he was missing in action, under a mortar strike.”

Eager to share their stories, other families clustered around a team of New York Times journalists, asking them to write down the names of their sons as well. They were all seeking news of men from the 81st Brigade who had gone missing in repeated Ukrainian assaults around Bilohorivka.

The battles for Bilohorivka and other places on the eastern front seldom make headlines. The government also restricts the publication of details of military casualties, to avoid sharing such information with Russia but also to prevent any lowering of morale at home.

For those reasons and others, families said, finding out what happened to individual soldiers has proved to be nearly impossible.

Lyudmyla Marchenko said her son Andriy, 37, enlisted last year and spent a month training in Britain, which he enjoyed, sending home selfies. But within 10 days of his return to Ukraine, he was sent to the front. He went missing in action in his first assault. “He’s my only son,” she said quietly. “It’s very hard.”

Families have learned from fellow soldiers about the devastating Russian shelling that has smashed Ukrainian lines.

“We started to receive information that a lot of soldiers are lying there and there is no way to retrieve them,” said Halyna Tsilitsinska, whose son, Oleksandr, went missing in April.

Many families cling to the hope that their missing sons and husbands are still alive, captured by Russian forces and now being held as prisoners of war. They write letters and visit offices, and spit into jars to provide DNA samples. They also scour the internet for news and photos, sometimes being misled by Russian scammers.

About 10,000 Ukrainians are being held by Russia as prisoners of war, according to human rights organizations, yet their names are unknown. Russia has refused to provide complete records of those being held. But to the frustration of many families, Ukraine also has declined to release the names of those it has confirmed are being held in Russian detention as it tries to negotiate prisoner exchanges.

The spokesman, Mr. Yatsenko, said the government could not publish personal data for reasons of privacy. And he added that Russia was contacting families and encouraging them to protest against the government in an effort to destabilize Ukrainian society.

The families demonstrating were supportive of the armed forces in their comments, but also made clear that they wanted answers. A small group carried a red-and-black flag from the Aidar Battalion, a little-known combat unit that has been in the forefront of fighting against Russia and Russian-allied separatist forces since 2014.

Russia has named Aidar as one of the right-wing, extremist and nationalist groups that were the declared reason for its invasion of Ukraine. But the deputy commander of the battalion, who used the call sign Hook, said Russia’s animosity for the group was more likely because it was drawn from local men from the eastern provinces who were opposed to Russian rule. “Aidar is like a bone in their throat,” he said.

The women with the Aidar flag said that as many as 100 men from the battalion were now missing. Information on their fate has been scarce, although 18 soldiers from the battalion, including two female nurses, appeared in a Russian court in July.

Pale and gaunt, and with their heads shaved, they were seen behind the plate glass of the defendants’ box in a Russian courtroom. They had been charged with being part of a terrorist organization, which carries a sentence of 16 years’ imprisonment.

The trial has been condemned by human rights groups as a violation of international conventions on the treatment of prisoners of war. For friends and family, it was a bittersweet moment to see them: relief that they were alive, mixed with pain at their condition.

“They looked terrible,” said Lyuba, 27, a decorated combat medic who is a friend and close colleague of the two women prisoners. “You could see clearly they had been tortured. They were very skinny. They had lost a lot of weight.” Her friend, Maryna, a 26-year-old nurse, now looked more like 40, she said. Lyuba, in accordance with military protocol, gave only her first name. Others gave only their call signs.

Interviewed near the frontline in Donetsk region recently, Lyuba and other members of Aidar agreed to be interviewed only if they could talk about their comrades.

Chichen, 26, an artillery unit commander who like Hook asked to be identified only by his call sign, said his best friend, Ihor Gayokha, 35, was among the prisoners. The battalion thought Gayokha, which is also his call sign, had been killed in an ambush in March last year before he appeared in video footage being interrogated on Russian social media channels.

Yet his mother, Nataliia, who was among those at the rally in Kyiv, said she still had received no official confirmation from either Russia or Ukraine that he is being held.

Human rights organizations have warned that once soldiers disappear into the Russian prison system it could be harder for Ukraine to bring them home, either in a prisoner exchange or in a general release at the end of the war.

And without his name on a list of prisoners of war, his mother said, she fears that there is less chance of his return.

“He is there in the court,” she said in frustration, “but he is not on any list.”