Here's what to know about the naval drones Ukraine uses to sink Russian ships in the Black Sea

A Russian ship named Caesar Kunikov passes through the Dardanelles strait in Turkey en route to the Mediterranean Sea, on Oct. 4, 2015.

The Ukrainian military said on Wednesday that it sank a Russian landing ship in the Black Sea using naval drones, though Russian authorities have not yet confirmed the report.

The Caesar Kunikov amphibious ship was sunk near Alupka, a city on the southern edge of the Crimean Peninsula that Moscow annexed in 2014.

Ukraine’s military said the attack had been carried out with Magura V5 – the same naval drone that was used in striking the Russian warship Ivanovets on February 1 – with explosions damaging the Caesar Kunikov’s left side.

According to Ukrainian state-owned foreign trade enterprise SpetsTechnoExport, the Magura V5 measures 5.5 meters in length and 1.5 meters in width. It exhibits a cruising speed of 40.7 kilometers per hour, a maximum speed of 77.8 kilometers per hour, and an operational range extending up to approximately 833 kilometers.

This unmanned maritime drone has a payload capacity of 320 kg of explosives.

Andrii Yusov from Ukraine’s Military Intelligence, known by its Ukrainian acronym GUR,  declined to say how many drones were deployed. But he told reporters that the operation took “a long time to prepare — routes are tracked, data is collected.”

The private intelligence firm Ambrey said a heavily edited video released by GUR showed that at least three drones conducted the attack and that the ship likely sank after listing heavily on its port side.

The destruction of the Cesar Kunikov is the latest in a series of Ukrainian drone and missile strikes against Russian ships and naval facilities that have helped break Moscow’s blockade of the Black Sea.

According to the Ukrainian Armed Forces, about a third of Russian combat ships on the Black Sea have been destroyed or damaged since the beginning of the war nearly two years ago. This includes 24 naval vessels and one submarine.