Police and military officers swooped down on a Moscow business center this week unannounced. They were looking for men to fight in Ukraine — and they seized nearly every one they saw. Some musicians, rehearsing. A courier there to deliver a parcel. A man from a Moscow service agency, very drunk, in his mid-50s, with a walking disability.

“I have no idea why they took him,” said Alexei, who, like dozens of others in the office complex, was rounded up and taken to the nearest military enlistment office, part of a harsh new phase in the Russian drive.

In cities and towns across Russia, men of fighting age are going into hiding to avoid the officials who are seizing them and sending them to fight in Ukraine.

Police and military press-gangs in recent days have snatched men off the streets and outside Metro stations. They’ve lurked in apartment building lobbies to hand out military summonses. They’ve raided office blocks and hostels. They’ve invaded cafes and restaurants, blocking the exits.

At a predawn sweep on the MIPSTROY1 construction company dormitories on Thursday, they took more than 200 men. On Sunday, they rounded up dozens at a Moscow shelter for the homeless.

The press-gangs appear to descend at random. It is terrifying — and, at times, comically haphazard. Alexei, a 30-something pacifist, lives with his cat and, until he was hauled off, enjoyed hanging out with friends in bars, cafes and parks, going to concerts and planning his next holiday in Europe. (He and others in this report spoke on the condition that his last name be withheld out of concern for his safety. The Washington Post has confirmed the raid but could not independently verify the details he provided.)

An official barged into Alexei’s office Tuesday. Two police officers and several plainclothes military officials arrived and demanded his identification. They ordered him to go with them quietly “or we will use force,” he said.

“I was panicking,” he said. “I’d never been detained before. Everyone knows that if you are detained by the police in Russia, it’s very bad.”

Suffering massive military casualties and repeated defeats in Ukraine, Russia has begun cannibalizing its male population. The hard-eyed pundits on state television are demanding more Ukrainian blood and more sacrifice from Russian men who they say have grown too used to soft living.

But the new phase of Russian President Vladimir Putin’s mobilization risks denting Russians’ tacit support for the war and even his manufactured popularity — and could stir social unrest. Particularly in Moscow and St. Petersburg, major cities that until now have been largely untouched by the war.

More than 300,000 Russian men and their families have fled Russia since mobilization, reports from neighboring countries indicate. Authorities have set up mobilization points at border crossings to prevent departures. Many others want to leave after seeing the aggressive police raids and the first reports of the newly conscripted men dying in the war.

Activist Grigory Sverdlin, who left Russia and is based in Georgia, this month launched an organization, Go By The Forest, to advise men in Russia on avoiding the draft. He said group has consulted with 2,700 men in 11 days and told 60 drafted men how to surrender in Ukraine. At least eight have succeeded, he said.

“Obviously, people are very stressed because they are worried they will be pushed to shoot other people,” Sverdlin said. “So people are afraid not only for themselves but about taking part in this unjust war.”

Yevgeny, 24, quit his job as a mechanic and is hiding at a relative’s dacha far from Moscow. He has deleted his social media profiles and cut contact with friends. He spends his days working in the garden, and he goes to bed early and watches a lot of YouTube.

“I don’t want to kill people, and I don’t want to be killed, so I really have to lie low now,” he said. “But even here, I don’t feel safe. We live at a time when your neighbors could report on you. They might call police and say that there is a young guy staying in this house when he should be fighting fascists in Ukraine.”

Yevgeny never supported the war. Now he has stopped driving for fear of being pulled over by police. He cannot leave Russia, because he has no passport, and even going to the store in the small village feels risky.

“I am panicking, and my mom is very nervous,” he said. “I’m stressed, and I’m depressed. I try not to think how long this could go on, because you can go crazy.”

Two of his friends are worse off. They were conscripted late last month, he said, and with little training are on their way to the front.

“I have a couple of friends who supported the war believing that there are Nazis there who kill poor Ukrainians and that Ukrainians should be liberated and so on. But they are changing their opinions after mobilization. They have started to ask questions and surf the internet for information,” Yevgeny said.

“They don’t want to die, especially when you don’t understand why you should die,” he said. “What is the point?”

Putin said Friday that 222,000 of the 300,000 target had been conscripted and that the process would be completed within two weeks. Pro-war hard-liners insist a second round will be needed.

The raids in Moscow and St. Petersburg have been deeply controversial, in part because the cities have suffered comparatively few casualties in Ukraine. The burden of fighting has largely been borne by small ethnic groups and poorly educated men from impoverished rural regions.

In a sign that the government fears a growing urban backlash over the raids, Andrei Klishas, a senior member of Putin’s United Russia party, said Friday that the conscription drives were illegal.

“It is inadmissible to grab everyone on the street indiscriminately,” he said.

Antiwar sentiment could harden as the bodies of soldiers who were deployed just weeks earlier begin returning home for burial. Alexei Martynov, the 29-year-old head of a Moscow government department, was mobilized Sept. 23 and was killed Oct. 10. He was buried last week. Five soldiers from the Southern Urals region, mobilized on Sept. 26 and Sept. 29, were killed in Ukraine in early October, authorities in Chelyabinsk reported.

A comrade of the Chelyabinsk men who survived an overwhelming Ukrainian assault called a friend and described what happened, according to the transcript of a phone call published by BBC News Russian. He said he had been given no training. When he fled, he said, corpses lay everywhere.

“We got there the first day, having never fired a shot, and they sent us, like meat, straight to an assault unit, with two grenade launchers. I had at least read the instructions on how to use them.” By Day 3, the soldier and his comrades were in front-line trenches.

Almost daily, videos surface on Russian social media of conscripted soldiers, angry because they have not been given decent uniforms, weapons, training or quarters. Testimonies about men who should be exempt being sent to fight are common. Aleksei Sachkov, a 45-year-old Moscow doctor, signed a contract to treat wounded soldiers in Voronezh, Russia, near the border with Ukraine. He stopped calling his wife, Natalia, on Sept. 24. She learned from Russia’s military hotline a week later that he was fighting in Ukraine as part of a tank unit, she said in a video posted online.

As unease grows, men of military age are being turned back at borders as they try to leave the country. In March, weeks after Putin launched the invasion, he promised there would be no mobilization. But last month, he dashed the tacit assurance that the conflict would be fought only by professional soldiers in return for the Russian public’s passive acceptance of the war. The widespread anger over Putin’s Sept. 21 announcement suggests that public support for the war is lower than the Kremlin claims.

“It’s the regime’s agony, because quite a common opinion in Russia now is that this war is lost,” Sverdlin said. “And it seems that just giving out summonses, detaining many thousands of people and sending them to war just buys this regime a bit more time. But it’s just buying time, because, obviously, these people who were caught on the streets now won’t make good soldiers because they don’t know how to fight.”

As the backlash intensifies, some Russians are confronting authorities and recording videos. A woman berated a team in the lobby of her St. Petersburg apartment building. A Russian truck driver posted video of himself confronting a police officer and a military enlistment official who tried to take him to the enlistment office.

“I don’t give a s--- about your mobilization. You’re the one who is eligible, not me. You’ve got a gun after all, not me. Why don’t you go mobilize yourself?”

The police officer tried to write a charge, demanding the driver’s documents.

“I’m not giving you my documents. Why should I?” the truck driver said, “If you fail to create order in your country, why do it in another country? And how? By just destroying it completely?”

In the rowdy hubbub of the military enlistment office where Alexei wound up, he said, many of the men were agitated, some were furious and others shrank into themselves. They queued at one office after another, where they were made to sign the military summons, submit their documents and undergo a medical examination. Many were office workers seized on the street. A couple of “strange ones” told Alexei they were volunteers, looking for an exciting lifestyle change.

He was shocked by how many men meekly donned the army uniforms that were handed to them and let themselves be taken, apparently directly to training bases. One of his work colleagues was among them.

“I saw men who were lost and confused, and at the same time very weak,” he said. “They didn’t want to fight for themselves. They were given papers and obediently signed them all. They weren’t focused. They just stared into space, as if they had given up.”

For Alexei, the threats and bluff continued for hours as officials pressured him to sign the military summons. He refused. Police were called. They took no action, but a police guard at the door would not let him leave.

He watched the queues of nervous men. The drunken city worker was in a deep sleep. A member of the elite Russian Guard special police threw a noisy tantrum about the attempt to enlist him.

Alexei called a lawyer. He entered the office of the military commissar, filming him on his cellphone, demanding to know the legal basis for holding him.

“He got very angry and shouted at me to leave his office.” At 8 p.m., he was finally allowed to leave. Now he wants to leave Russia but fears he could be conscripted at the border.

“I want to wait until this is over, in a safe place.”