Two Ukrainian navy ships pass through Russian-controlled Kerch Strait (VIDEO)

In a move that immediately raised tensions in the Azov Sea, two Ukrainian navy ships passed under Russia’s illegal bridge over the Kerch Strait late on Sept. 23 in a surprise deployment to the area.

Surrounded by a small flotilla of Russian warships, and buzzed by low-flying Russian aircraft, these were the first large Ukrainian naval ships to be deployed to the region since the Kremlin launched its war of aggression on Ukraine in 2014.

The ships, the search and rescue ship Donbas and the tugboat Korets, which both left Odesa on Sept. 20, are now heading to the port city of Mariupol and are expected to dock there on the evening of Sept. 24, according to the Ukrainian Military Portal.

“Ukraine’s Naval Forces will not allow the aggressor country (Russia) to turn the Azov Sea into its internal lake,” Ukraine’s Naval Forces Command said on its Facebook page on Sept. 24, announcing the successful passage of the Donbas and Korets through the Kerch Strait.

Having entered the Azov Sea, the two naval ships were met by two Ukrainian armored fast patrol boats, the Kremenchuk and Lubny, which came from their base at the port of Berdyansk to meet them.

There was also a military presence in the air to support the Ukrainian ships, with a U.S. Boeing RC-135V reconnaissance aircraft patrolling the area.  

In the Kerch Strait, the Ukrainian navy ships sailed past more than 10 Russian warships, which made no attempt to stop them.  

The search and rescue ship Donbas and the tugboat Korets pass through the Kerch Strait on Sept. 23.

Ukrainian naval expert Taras Chmut said the Russian navy most likely didn’t expect Ukraine’s ships to risk passing through the Kerch Strait. But when they did, the Russians chose the least risky option and allowed them through.

“We seized the initiative,” Chmut said. “For the first time, we didn’t just react to the Russians’ steps, but started to set our own game rules.” 

However, the Russians had already responded aggressively to the approach of the two Ukrainian ships, according to the naval command report. 

On Sept. 20, the Priazovye, a Russian reconnaissance ship, sailed dangerously close to the Ukrainian vessels, and on Sept. 21 a Russian SU-27 fighter jet came close to colliding with a Ukrainian An-26 military transport aircraft in the same area over the Black Sea. 

The deployment of the lightly-armed Ukrainian naval ships is the first time Kyiv has tested the Kremlin’s strengthening grip on the Black and Azov Seas. When Russia seized the Ukrainian territory of Crimea it also gained control of the Kerch Stair, the only route navigable for large ships to Ukraine’s ports on the Azov Sea.

This May, when Russia opened the Kerch Bridge connecting its territory to Ukraine’s Russian-occupied Crimea, Russian coast guards began to halt and search merchant vessels in the Azov Sea, which according to treaty is under shared use by Ukraine and Russia.

The Russians have since halted more than 170 of Ukrainian and foreign trade vessels, according to Ukraine’s border guard service, causing huge losses to Ukraine’s Azov Sea ports in Mariupol and Berdyansk.

In response, Ukraine’s government announced plans to open a naval base in Berdyansk by the end of the year. Ukraine earlier in September sent three patrol boats overland to reinforce its fleet in the Azov Sea.

For the Donbas, which was built 1969 and had been due to be scrapped this year, it was one of the longest trips in its history, Chmut said. 

Now it will serve as a floating naval base until the necessary infrastructure is built in Berdyansk, he said.