The government of President Nicolás Maduro is detaining and intimidating doctors, marking the homes of people suspected of having the virus and detaining those who are returning to the country. Venezuela is deploying security forces in its coronavirus crackdown.

President Nicolás Maduro of Venezuela has tackled the coronavirus much as he has any internal threat to his rule: by deploying his repressive security apparatus against it.

Officials in Venezuela’s government are denouncing people who may have come into contact with the coronavirus as “bioterrorists” and urging their neighbors to report them. The government is detaining and intimidating doctors and experts who question Mr. Maduro’s policies on the virus.

And it is corralling thousands of Venezuelans who are streaming home after losing jobs abroad, holding them in makeshift containment centers out of fear that they may be infected.

In commandeered hotels, disused schools and cordoned-off bus stations, the returning Venezuelans are forced into crowded rooms with limited food, water or masks and held under military guard for weeks or months for coronavirus tests or treatment with unproven medications, according to interviews with the detainees, videos they have taken on their cellphones and government documents.

In one major city, San Cristóbal, governing party activists are marking the homes of families suspected of having the virus with plaques and threatening them with detention, residents said. In another city, Maracaibo, the police are patrolling the streets in search of Venezuelans who re-entered the country without official approval. Local opposition politicians whose constituencies register an outbreak say they are threatened with prosecution.

“This is the only country in the world where having Covid is a crime,” said Sergio Hidalgo, a Venezuelan opposition activist who said he had come down with symptoms of the virus, only to find police officers at his door and government officials accusing him of infecting the community.