"Due to the injuries, the ferry sank in the harbor in Kavkaz", writes the region's operational headquarters on the messaging site Telegram.
Kavkaz is located in the Krasnodar region in Russia, opposite the annexed Crimean peninsula.
Earlier on Thursday, Russia reported that it had taken another small community in Donetsk.
Thus, the Russian advance towards the city of Pokrovsk continues, which is described as a logistically important hub in the region.
The village of Mezjove – between Avdiivka and Pokrovsk – is the latest in a long series of alleged Russian conquests in the area. Lack of manpower and ammunition has caused Ukraine to suffer setbacks in the region, while Russia has pushed forward.
In Pokrovsk and its surroundings, the evacuation of civilians is now underway as Russian forces approach.
Further west, President Volodymyr Zelenskyj visited the border area with Russia on Thursday. It is his first visit to the area since Ukrainian forces crossed the border over two weeks ago.
During his visit to the Sumy region, the president praised the Ukrainian forces' progress in Russian Kursk.
Zelenskyj also stated that discussions are underway to strengthen the defense around Toretsk and Pokrovsk in Donetsk.