A 38-year-old man was jailed for a maximum of three years in the southeastern town of Dimitrovgrad after being found guilty for violating a law that requires citizens to respect medical orders during an epidemic, news portal Juzne Vesti reported.
All Serbian citizens returning from abroad are required to spend 14 to 28 days in self-isolation.
The man broke this rule at the airport in the southern town of Nis upon his return to Serbia earlier this month, the report said.
He was tried online and entered a plea from detention, while the judge, prosecutor and a court-appointed lawyer were in the courtroom, following instructions from the justice ministry, the report added.
Two other people were sentenced to two and two and a half years respectively in the eastern town of Pozarevac for breaking the same measure, N1 television network reported.
A total of 111 people have been detained for the same offence, N1 said.