Vasyl Malyuk, the head of the Security Service of Ukraine (SBU), said his agency was behind the attack, speaking in comments shown on television as he presented a commemorative postage stamp marking wartime special forces operations.
"There were many different operations, special operations. We'll be able to speak about some of them publicly and aloud after the victory, we will not talk at all about others," Malyuk said.
"It is one of our actions, namely the destruction of the Crimean bridge on October 8 last year."
The bridge was badly damaged in October in a powerful blast, with Russian officials saying the explosion was caused by a truck that blew up while crossing the bridge, killing three people.
The bridge was hit by a fresh attack this month but Malyuk made no mention of who was behind that one.
The 19km Crimean Bridge over the Kerch Strait is the only direct link between the transport network of Russia and the Crimean peninsula, which Russia annexed from Ukraine and occupied in 2014.
The bridge was a flagship project for Russian President Vladimir Putin, who opened it for road traffic with great fanfare by driving a truck across in 2018.
It served as a crucial supply route for Russian forces after they invaded Ukraine on February 24, 2022, sending forces from Crimea to seize parts of southern Ukraine's Kherson and Zaporizhzhia regions.
