Euromaiden, a group of protesters calling for European integration, has reported on its website that 66 citizens were missing.
But police said that the information included unverified phone communication data.
Authorities also said they have only received complaints about the disappearance of three people, and those notifying authorities have not linked those individuals with Euromaiden, Interfax-Ukraine reported.
Some of the people on the list are in custody, and police are checking all Internet reports about missing people.
Ukraine has been rocked by anti-government protests after President Viktor Yanukovych refused to sign trade and association agreements to bring the former Soviet republic closer to the European Union.