Photo taken on Nov. 26, 2018 shows three Ukrainian naval ships seized by Russia. (Xinhua/Sputnik)

MOSCOW, Nov. 28 (Xinhua) -- Russian President Vladimir Putin said Wednesday that the Kerch Strait incident was a provocative attempt by Ukraine and its president to escalate tensions with Moscow to add pressure on his political rivals.

"As for the incident in the Black Sea, it was a provocation organized by the incumbent authorities and, I think, by the incumbent president, ahead of the presidential elections in Ukraine next March," Putin told an annual investment forum.

On Sunday, three Ukrainian naval ships attempting to sail through the Kerch Strait from the Black Sea to the Sea of Azov were attacked and seized by Russian forces, which claimed that the ships violated the Russian border.

The Ukrainian Navy said that it had informed Russia in advance of the passage of its vessels through the strait, while Russia said it had received no such report and the ships ignored multiple warnings by the Russian border guards.

The Russian Federal Security Service (FSB) confirmed on Monday that Ukrainian Navy's "provocative" actions were devised by Kiev and coordinated by two officers of the Security Service of Ukraine.

Putin accused Ukrainian President Petro Poroshenko of making noises in the region to boost his declining popularity ratings before an election next year.

"It has nothing to do with attempts to settle the relations between Russia and Ukraine. It is a game of aggravation. It is an unscrupulous game inside the country with the aim to crush political opponents," Putin said.

Following the conflict, the Ukrainian parliament on Monday supported a bill imposing a martial law in certain regions bordering Russia for 30 days.

Putin said it was unreasonable for Kiev to introduce martial law over a "minor border incident" in the Black Sea, considering that no martial law was imposed even when the Ukrainian civil war broke out in 2014.

Ukraine has accused Russia of "aggressive actions" in the Sea of Azov after Russia inaugurated a bridge over the Kerch Strait earlier this year and started inspecting commercial ships sailing through the sea and the strait.

Moscow rejected such accusations, saying Russia can exercise its sovereign rights in nearby waters off Crimea and the Kerch Strait is not an international passage.

Relations between Russia and Ukraine have been deteriorating since Crimea was incorporated into Russia in March 2014 following a local referendum, which was rejected by Kiev and Western countries.