Officials say at least ten people have died in floods after torrential rains and hail lashed the Balkan country late on Thursday.
"The situation is beginning to calm down but it is still critical," Interior Minister Tsvetlin Yovchev said Friday, adding that several people are believed to be missing.
Nine of the victims were in the Black Sea port city of Varna, which was worst-hit by the bad weather. Speaking from a suburb of the city, Varna Mayor Ivan Portnih said the "tragedy is enormous."
"The street is not here, the houses are not here, there are cars on top of each other," he said, adding that some electricity in the suburb had been cut off.
Relentless rainfall has hampered rescue efforts, and the extent of the damage is not yet known.
Weather forecasters said the rains that fell in the country's east in the past 24 hours was equivalent to the usual amount for the entire month, and warned new rainfall and thunderstorms were expected later on Friday.
In May, at least 40 people died when neighboring Balkan countries Serbia, Bosnia and Croatia were hit by the heaviest rainfall since records began 120 years ago.
nm/hc (Reuters, AFP, dpa)