Schools and pharmacies of Bulgaria were gripped by panic-fuelling rumours about a radiation in "a nearby country" that made people rush for medicines on Thursday.
It was not immediately known where the information came from, but people were told that a radioactive rain over Bulgaria had spread the deadly threat.
Bulgaria's civil defense office said it had received scores of worried inquiries. However, there was no reason of scare from nuclear accident, they said ruling out reports about a nuclear accident in Romania's Cherna Voda plant, and later, at a unit in the Russian town of Balakovo.
Romanian authorities said there was no incidents of any type at Cherna Voda, which is located near the country's Danube River bordering with Bulgaria. Russian authorities have also denied any radiation leaks.
The rumours spread the same day that the report on the environmental impact of the Belene nuclear plant was completed and the results were announced.