Nearly 97% of people who went to the polls voted against the municipal council and mayor issuing and approving development plans and permits for the extraction of metallic minerals on its territory, the referendum results posted on the commission's website showed.
Voter turnout stood at 59%, which is above the 40% required for the proposal to pass.
The decision can be appealed to the Sofia district administrative court within seven days.
The referendum concerns the Zlatusha gold and copper property. In 2018, the Bulgarian energy ministry granted Zelenrok, a local subsidiary of Australia's Raiden Resources, a three-year prospecting and exploration permit for the site, according to previously disclosed information.
Last January, Canada's Velocity Minerals said it signed a binding agreement with Zelenrok with a view to incrementally purchasing up to 75% of the Zlatusha project. Velocity Minerals then announced plans in November to begin drilling at the property in the first half of 2024 after initial exploration yielded positive results.
Last month, Velocity said it will apply to extend the term of the Zlatusha prospecting and exploration licence by an additional two years.
In Bulgaria, Eastern Europe-focused Velocity Minerals owns 70% interest in each of the Tintyava, Momchil, Nadezhda and Dangovo properties, along with 100% in the Iglika copper-gold property in southeastern Bulgaria.