Footage circulating on social media shows explosions in Crimea as fierce fighting between Russia and Ukraine rages.
Russia’s defense ministry has accused the Ukrainian Armed Forces tried to attack the Novorossiysk naval base at night with two unmanned marine boats.
In the clip, a blast is seen on the water as smoke billows, but it is unclear what is being targeted.
They added that Russian ships destroyed the naval drones in what would be the first attack targeting the port city.
Ukraine has yet to comment on the incident.
Novorossiysk hosts the terminus of a pipeline that carries most Kazakh oil exports through Russia.
The Kyiv Post reported the explosions were heard in Feodosia, also in Crimea.
The Crimean peninsula was annexed by Russia in 2014 and has come under more intense, increased attacks in recent weeks as Kyiv pushes back.
Kyiv has repeatedly said it plans to take back Crimea.
It comes after drone footage was released showing the moment 200 troops are taken out by a Ukrainian HIMARS strike.
The training camp on Dzharylhach Island, in occupied Kherson, is situated close to the Black Sea – and Russian troops can be seen in formation.
Five American HIMARS rockets are then deployed as targets lock onto several different fighter groups.
