Georgian authorities say heavy rainfall and flash floods overnight left several people dead, with many others missing in the capital, Tbilisi.
The city's zoo was also flooded, allowing tigers, lions, wolves, and other animals to escape.
On June 14, government officials said the death toll had reached 13. Interior Minister Vakhtang Gomelauri said a further 24 are missing.
Prime Minister Irakli Garibashvili has declared June 15 as a day of mourning.
Heavy rains started late in the evening on June 13, turning the Vere River flowing through Tbilisi into a torrent that swept away dozens of buildings and cars and damaged power lines.
Rescue workers were searching submerged buildings to check for trapped residents.
Tbilisi Mayor David Narmania said the situation was "very grave."
PHOTO GALLERY: Scenes of destruction in Tbilisi
Three zoo workers were killed in the flooding. One of the dead was Guliko Chitadze, a zookeeper who lost an arm in an attack by a tiger last month.
Local Rustavi 2 television reported that police have shot dead several animals over safety concerns, with six wolves killed at a children's hospital.
The zoo said an escaped hippopotamus was cornered and subdued with a tranquilizer gun.
Some other animals have also been captured, but it remains unclear how many are on the loose. Tbilisi Mayor Davit Narmania told an emergency cabinet meeting that some animals "unfortunately had to be killed because they represented a danger to the residents."
Helicopters were circling the city early on June 14 and authorities asked residents to stay indoors while the search for the animals goes on.
There were no immediate reports that any of the dead were killed by the animals, which ran off after the floodwaters destroyed their enclosures. Among the beasts that escaped were bears, wolves, and monkeys.
Other animals were hunted down and killed.
The carcasses of at least a lion, a boar, and a tiger were seen, and zoo authorities said six wolves were also dead.
Authorities said the animals may have fled to just about any corner of Tbilisi, including the forests on the steep hills in the city's heart.
President Giorgi Margvelashvili offered his condolences to the families of the flood victims and promised that the process of rebuilding would quickly begin.
Finance Minister Nodar Khaduri put the estimated damages at some $18 million.
"Dozens of families remain homeless as their houses were destroyed or damaged in the capital," Lekvinadze told reporters.
Heavy rains also caused a landslide on the Tskneti-Betania road outside the capital.
Police helicopters evacuated 16 people from Akhaldaba outside Tbilisi, where heavy rains damaged roads.
About 1.1 million people live in Tbilisi.
With reporting by Interfax, Reuters, AFP, AP, and dpa