Ukrainian forces attacked a railway ferry at the Kavkaz port in Russia's Krasnodar on August 22 - RIA Novosti reported, citing local emergency services.
The missile attack is believed to have caused a major fire and a fire truck has been dispatched to the scene.
So far, there have been no reports of casualties. Fedor Babenkov, head of the Temryuk district where the capital is located, wrote on his official Telegram account that the targeted ferry was carrying 30 fuel boxes.
He added that 12 fire teams and 3 rescue teams were working at the scene.
According to the Telegram channel of the Russian Defense Command Krasnodar, more than 100 people participated in extinguishing the fire, including 43 people from the Russian Emergency Ministry, the unit also contributed 13 units of equipment.
RIA Novosti quoted Russian emergency services as saying that five people were believed to be on the ferry when the missile attacked. According to the news agency, their fate remains unclear.