Civil defence sirens will sound in a test on April 1 at 1pm in Sofia and several other places in Bulgaria, the Interior Ministry said.
Sirens will be tested, apart from in the Bulgarian capital city, in Plovdiv, Varna, Bourgas, Kurdhzali, Montana, Pazardzhik, Pleven, Smolyan, Vratsa and in settlements in the 30km zone around the Kozloduy nuclear power station.
The sirens will be accompanied by tests of voice warnings.
The Interior Ministry issued a reminder that the system is tested twice a year, on the first working day of April and of October.
(Photo: Bulgaria Interior Ministry press centre)