The attacks took place in the Sea of Azov and the ships were set on fire, according to Commander Robert Brovdi.
A total of 36 Russian ships have reportedly been hit since Ukraine began its offensive to try to cut off logistics to the Russian-occupied Crimean peninsula. However, the number is not confirmed, as some ships may have been hit multiple times.
On Wednesday, two Russian tankers were hit by Ukrainian attacks, Bloomberg previously reported.
According to the Russian governor of Rostov, the ships were fired upon in Taganrog Bay, the farthest point into the Black Sea east of Crimea, and were still burning on Thursday.
During the night of Thursday, Ukraine also attacked a fuel warehouse in Tver, north of Moscow, reports NTB.
