The Russian military blogger said the attack was unsuccessful and the main bridge worked after a brief closure.
Ukraine's SBU Security Agency said it had hit a bridge with Russia and Ukraine's annexed Crimea Peninsula below the water level and the annexed bridge of explosives, a key supply line for its third attack on Russian forces in the war-torn country.
Around 1,100 kilograms (2,420 pounds) of explosives were exploded Tuesday morning during the action prepared within months to destroy the underwater pillars of the bridge over the bridge strait, the SBU statement said.
"Previously, we hit the Crimea Bridge twice in 2022 and 2023. So today we continue that tradition." "The bridge is now effectively in a state of emergency."
SBU shared a videotape, claiming to show an explosion next to one of the many supporting pillars of the bridge.
The Russian military blogger said the attack was unsuccessful and speculated that it was carried out by Ukrainian sea drones.
Russian official media has provided regular status updates on the bridge, saying its operations have been suspended for about three hours between 4 a.m. and 7 a.m. local time (01:00 and 04:00 GMT).
It has no reason to close temporarily, but says the bridge has reopened and is functioning properly.
The only direct link between the Russian and Crimean transportation network and the Russian transportation network annexed from Ukraine in 2014 from Moscow and the Crimean Peninsula, which is the 19 km (12 miles) Crimean Bridge.
The bridge is the flagship project of Russian President Vladimir Putin. It consists of a separate road and railway, both supported by concrete stilts, and between the Black Sea and the smaller Azov Sea, the steel arches occupy a larger span through the steel arches.
Russian troops used the bridge when they invaded Ukraine in February 2022, when they crossed it to Crimea, and then occupied parts of the southeastern region of Hessen and Zaporizhia in southern Ukraine.
The attack was targeted by Russian troops in the city of Ukraine, killing at least three people and causing many injuries, the city council and the Ministry of Health said.
Ukrainian President Volodymyr Zelenskyy said at least one rocket launched from multiple rocket launchers failed to detonate and was sent in the apartment building.
"That's all Russia wants to end this war," Zelenskyy said on his telegram channel.
Russia told Ukraine during peace talks in Istanbul on Monday that it would only agree to end the war if Kiev abandoned most of its territory and accepted restrictions on the size of its army. Ukraine repeatedly rejected Russian conditions because Russian conditions involved surrender.