Tensions between Russia and Ukraine remain high. In yet another expression of hostility, the Russian government paraded the captured Ukrainian sailors on television. The men — clearly under duress — acknowledged the fault of their actions and apologised for them.

The skipper of the Ukrainian flotilla, Volodymyr Lisovyi, said, “I deliberately ignored requests via ultra-short-wave band and was aware of the provocative nature of our actions.”

One of the sailors, Andriy Drach, added, “We were warned by the border service of the Russian Federation that we were violating Russian law. They had repeatedly asked us to leave the territorial waters of the Russian Federation.”

Moreover, the Russian military announced that it will deploy additional S-400 anti-air batteries in Crimea to counter any Ukrainian or Western aggression. In the meantime, a Crimean court ordered that 12 — half of the captured Ukrainian sailors — be detained for two months. A verdict for the remaining 12 crew members is expected soon.

The Kremlin, moreover, warned that Ukraine’s declaration of martial law could deter the situation even more. Russian President Vladimir Putin said that the whole affair had been prepared by Ukrainian President Petro Poroshenko in an attempt to boost his ratings for the upcoming presidential elections. “He had to do something to make the situation more tense,” added Putin.

For his part, Ukrainian President Petro Poroshenko warned that there is a threat of a full-blown war with Russia. He added that in recent months “the number of [Russian] tanks at bases located along our border has grown three times.”

The chief of the Ukrainian Navy, Vice Admiral Ihor Voronchenko, tried to boost the spirits of the captured sailors. In a letter, he wrote that “It is normal to be afraid. The main thing is to believe in your will, defend your dignity and to remember that entire Ukraine is with you… All sailors understand what is behind your ‘testimonies’, we all know how Russian special forces work. I went through this in 2014 and I know what it means to be captured and what every word you say during the interrogation means.”

On Sunday, Russian Navy patrol boats carrying special operations forces (SOF) seized three Ukrainian Navy vessels that were heading toward the port of Mariupol, which is situated on the Sea of Azov. As a response, the Ukrainian government declared martial law.

The two countries have been on bad terms since the illegal Russian invasion and annexation of Crimea in 2014. This outward show of hostility has led to the ongoing undeclared war in the Donetsk region, in Eastern Ukraine. There, Russian-backed separatists are fighting the Ukrainian military, which is advised, trained, supported and supplied by NATO members.

Possible reasoning behind Moscow’s latest aggression in the region is the sovereignty of the Kerch Strait. The sovereignty of the Kerch Strait translates into sovereignty over Crimea. Earlier this year, Russia opened a bridge that connects mainland Russia with annexed Crimea. This was the bridge that the Ukrainian vessels were trying to navigate beneath when the Russians pounced. Thus, both sides perceive the Strait as an important key structure.