( CNN ) -- At least 11 people have died in Varna , the largest Bulgarian city on the Black Sea , as a result of massive flash flooding and mudslides , the Interior Ministry said . Some of the victims are children , the ministry said . Dozens were still missing , and tens of thousands were without electricity , the ministry said . The floods swept through parts of the port city Thursday and the rains continued Friday . City boulevards and streets have turned into rivers and many of the pedestrian underpasses are completely flooded . The heaviest hit district is Asparuhovo , where most of the streets are impassable , filled with smashed and overturned vehicles and uprooted trees . Some 4.3 inches of rain , more than double the monthly average , fell in Varna in a 48-hour period . The weather system responsible for this flooding has been progressing very slowly across southern Europe this week , and has spawned tornadoes in Italy , Greece , and Turkey , including near Istanbul . The storm system was beginning to move off to the northeast , but some more light rainfall was expected for eastern Bulgaria for the next 24 hours or so . Bulgarian authorities have declared an emergency in the region . Friday was declared a day of mourning for the victims . CNN 's Brandon Miller contributed to this report .
Floods swept through much of the city ; rain fell . More than double the average monthly rainfall falls in 48 hours . Slow - moving storm surge has spawned tornadoes in Italy , Greece , and Turkey . A day of mourning has been declared ; at least 11 died .