The three young women, participants in an antiwar chat group, were falsely accused last fall by one of its members of plotting with him to firebomb a military enlistment office.

The trio quickly went underground, hiding in a friend’s house in their home city of Vladivostok, in Russia’s Far East, while seeking a way to escape the country and potentially lengthy prison sentences. That brought them to a group called In Transit, part of an extensive underground railroad that is rescuing hundreds of Russians who have been targeted for expressing opposition to the invasion of Ukraine or even sympathy for Ukrainian refugees.

Their flight to freedom would ultimately end in Kazakhstan, after a six-day odyssey in six different cars over more than 4,000 miles — the equivalent of driving from New York City to Alaska. They were not told the route they would take, the names of the drivers or the rendezvous points until they reached each new city.

“We were scared,” said one of the young women, all students, aged 16, 17 and 19 — so much so that they avoided talking to people in the streets when they switched cars for fear of informers and surveillance cameras.

In Transit, the group that arranged their escape, is one of at least five organizations that help dissenters to get out of Russia, usually just one step ahead of the law. Working from outside the country, they plan escape routes that can include cars, travel money, safe houses, border crossings and visas.

“In a situation where everyone is against you, including your own relatives, who think that you are a traitor and are ready to hang you from the nearest lamppost, I was extremely pleased to discover that there are people who don’t know you at all, who’ve never seen you, and they are ready to help,” said Oleg Zavyalov, 31. He had just had a tearful reunion with his older brother, Vladimir, months after the siblings fled to different countries from the city of Smolensk in western Russia.

In Transit was the brainchild of three women from St. Petersburg, Russia, who realized that people caught up in the sweeping arrests of antiwar protesters after the invasion last February would need help getting out. For security reasons, they set up shop in Berlin. For the same reason, The New York Times is withholding the names of the founders and granting anonymity for those escapees who requested it, as well as details about the routes they took.

After the European Union largely stopped issuing visas for Russians last year, a few countries — mainly Germany, Poland and Lithuania — extended a humanitarian visa program, originally intended for Belarusian dissidents, to Russian opponents of the war.