Rumors spread quickly in wartime Ukraine.

They lived in an abandoned house in a forest next to a small village. They survived on mushrooms and berries. And it took months after the Russian Army retreated for the Ukrainian police to finally capture them.

Or so the story went.

At least four Ukrainian news media outlets and countless people on social media last week repeated the tale of six abandoned Russian soldiers. It turned out to be baseless, but it provided the latest vivid example of how wartime rumors — and possibly propaganda — spread quickly in Ukraine.

Vitaliy Romas, a former mayor of Dernivka, a village just east of the Ukrainian capital, Kyiv, where the soldiers were supposed to have been holed up, said he received more than 30 phone calls in one day. The police, military, journalists and people who were just curious called to ask about the supposed capture of the six Russians, he said.

Similar stories of left-behind Russians have circulated around the country. In one case, a Russian was said to be living in a root cellar and eating only pickles for months. In another, a group of soldiers apparently became so bold that they started a fight in a village, and were arrested by the police.

While seemingly harmless, such tales may have their origins in Russian propaganda, according to analysts monitoring Russian disinformation campaigns in Ukraine, spreading fear and keeping the police distracted investigating them. “There is a technology for spreading small fakes in the form of rumors,” said Andriy Shapovalov, the acting head of the Center for Combating Disinformation at Ukraine’s national security council.

The main characteristic of such rumors is the absence of a specific source of information. When people hear a story on the streets, they are typically unaware it may have been coordinated and planted, Mr. Shapovalov said. In fact, spreading rumors on buses or subway cars has been an approach throughout Russia’s yearslong conflict in eastern Ukraine, Mr. Shapovalov said, part of Moscow’s “hybrid war” approach, employing a blend of military, political and information operations.

“In the conditions of the hybrid war, which has been going on in Ukraine for more than eight years, it is normal to doubt everything,’ Mr. Shapovalov said.

The story of the captured soldiers reverberated quickly. One Ukrainian publication cited a Facebook post as the source. People discussed it online and in private conversations. Iryna Prianyshnykova, a spokeswomen for the Kyiv region’s police, confirmed that the story was fake.

She said the police regularly check out such fake stories and reach out to the news media to try to stop their spread. “Such stories are directed not only at police, so that we have more unnecessary work,” Ms. Prianyshnykova said, “but mainly at people, to create tension.”

In the village of Dernivka, people said they had heard nothing about Russian soldiers hiding among them. The village has only 450 people, and they all know one another. “People should think better,” Mr. Romas said. “We are a tiny village. We know every empty house — no one would be able to hide here.”