Loud explosions were heard in Odessa at 6:11 p.m., the city's mayor Gennady Trukhanov reported on the Telegram app, BTA reported.
The explosions occurred three minutes after the alarm was sounded. The missiles were launched from Crimea, local Telegram channels report.
Regional authorities are urging the population to hide in bomb shelters until the alarm is lifted. There is a risk of repeated missile launches.
The Bulgarians in the Odessa region number over 150,000 people and are the third largest according to the official census in Ukraine in 2001. About 50-60 thousand Bulgarians live in the city of Odessa itself. The largest compact Bulgarian population is concentrated in the Bolgrad, Izmail and Belgorod-Dniester regions.