How did Ukraine manage to attack a key port and sink a ship well behind Russian lines? No one’s quite sure yet, the Wall Street Journal reports, but the apparent success may create even more problems for Russia’s attempts to seize Mariupol. Berdyansk had been a key supply point, and seemingly out of range of Ukraine until this morning.

Videos taken of the port and the ship appear to corroborate the claims:

Ukraine said it struck the Russian-occupied port facilities in the Azov Sea city of Berdyansk, Thursday, setting off a large fire and destroying a Russian ship as the war entered its second month.

The port has become a major logistics hub for Russian forces. Footage from the area showed smoke billowing from the berthing area and Kyiv said the attack destroyed the Russian navy landing ship Orsk.

The attack in Berdyansk, nearly 100 miles from the main frontline in southern Ukraine outside the besieged Ukrainian port in Mariupol, is a sign Kyiv has retained significant military capabilities as it pursues a large-scale conventional war against Russian forces.

Russian officials didn’t immediately confirm the attack. Footage from Berdyansk shows other Russian vessels fleeing the port after the explosions.

Some photos are floating around on social media, with this one coming from the Kyiv Independent:

Russian landing vessel Orsk is now to meet Sponge Bob at the Berdyansk port. pic.twitter.com/bi717aVHbS

— Illia Ponomarenko 🇺🇦 (@IAPonomarenko) March 24, 2022

This video appears to give the best look at the destruction of the Orsk, and of at least one Russian naval vessel fleeing the port as it sinks:

«Footage of the operational withdrawal of ships after an emergency in the port of Berdyansk», as described by Russian backed channel.

Hmmm. Just a way of thinking. Heart a song «Fire I like what you’re doing to me». pic.twitter.com/WCzAKZavBX

— Ha Je (@herjans56) March 24, 2022

There may have been another ship damaged that retreated as well:

A photo from Berdyansk shows that a second large Russian navy landing ship was also heavily damaged in the Ukrainian missile strike. #UkraineWar pic.twitter.com/YQJFrpZXEg

— MelvinB📡 (@MelvinBGlobal) March 24, 2022

Berdyansk fell to Russia in the first days of the war, part of Vladimir Putin’s plan to cut off Ukraine from its access to the Sea of Azov. That part of Putin’s plan was among the small number of objectives his army and navy managed to achieve, and it appeared that their grip on the port was impenetrable. The Orsk was one of their resupply ships, used to send badly needed men and materiel to the front line in their largely  stalled push into Mariupol, the key to moving into the center of Ukraine.

If the Russians have lost the capability for resupply at Berdyansk, that does not bode well for its siege on Mariupol. Even if the Russians keep control of the city, it’s not worth a lot if they can’t exploit the port. It’s been a long time since the Russians had the momentum in Ukraine, and if the Ukrainians can strike at the Russian rear and cut off their supplies, it might allow Ukraine to seize momentum and go on the counteroffensive in the south against demoralized and cut-off Russian soldiers.

CNN wonders how the Ukrainians pulled this off:

Russian military ship destroyed in the occupied port of Berdyansk, Ukraine claims.@JohnBerman and @PhilBlackCNN have the latest on what this means for the Ukrainians as the war enters its second month. pic.twitter.com/1CNIg2k4dU

— CNN (@CNN) March 24, 2022

It’s a good question. Sabotage seems unlikely, given the scale and impact of the attack. This looks like a military operation, but it’s still not clear if it came from the land or the sea. The WSJ report notes that Ukraine does have some limited short-range ballistic missiles, but Berdyansk might be a bit beyond their reach at the moment. The Ukraine navy still remains in the fight but has been careful not to pit itself against the Russia fleet in the region, at least that we’ve seen thus far.

One report credits the Ukraine army in a kind of commando strike, and that the ships weren’t the only targets:

Soldiers of the Armed Forces of Ukraine, in addition to destroying the occupants’ warship Orsk, damaged two other enemy vessels. This was reported by Channel 24 with reference to its sources in the Zaporizhzhia regional civil-military administration.

According to them, in addition to the ships, the AFU fighters managed to destroy a fuel storage facility with a capacity of 3,000 tonnes. And then the fire spread to the enemy’s ammunition depot. Details of the damage inflicted to the occupant are still being specified.

On the other hand, Ukraine’s navy appeared to take credit for it:

A Russian-controlled port in southern Ukraine, the capture of which was heralded as a “milestone event” in the war by Vladimir Putin’s military, is now burning, and a tank-landing ship docked at the port has been sunk, according to the Ukrainian Navy.

Videos on social media purportedly showed the Port of Berdyansk in flames on Thursday morning. The Ukrainian Navy says the Orsk Russian tank-landing ship was destroyed at the port, and media reports indicate that two other ships are “smoking heavily and trying to escape.” A warehouse with ammunition and fuel was reportedly destroyed at the port as well.

Who knows? More importantly, Ukraine might not want the Russians to know how they accomplished the attack. It’s better to keep them guessing and over-commit resources in the wrong directions as a result, not to mention give the actual resources time to escape.

The timing was especially bad for Russia as well:

On Wednesday, the Kremlin-funded media outlet RT shared a video on social media showing Russian combat operations at the port.

The RT report showed the Orsk docked at Berdyansk, bringing heavy equipment and other supplies to front lines. …

A Russian military official interviewed by RT heralded the capture of the now burning port.

“Our arrival here is a milestone event. It opens up completely new opportunities for the Black Sea Fleet to use existing Ukrainian infrastructure for our logistics operations,” the unnamed military official said.

That’s at least off the table for a short time, and perhaps longer than that. Just getting the wreck of the Orsk out of the way will take time and keep that part of the port from operating.  Now that the Ukrainians have shown the capability to target Russian operations at Berdyansk, they will have to figure out just how much more men and materiel they wish to risk at the port. In the meantime, that will hit their resupply at a very bad time for their siege on Mariupol. Or at least so the Ukrainians must hope.