Video shared on social media on Saturday shows smoke coming from the Kerch Bridge linking Moscow-occupied Crimea with Russia's mainland.
The bridge has been the scene of recent Ukrainian attacks and the latest images of smoke billowing from it sparked speculation on X (formerly Twitter) about its cause.
Sergey Aksyonov, the Moscow-appointed head of the peninsula which Russia annexed in 2014, wrote on Telegram that "air defense forces shot down two Ukrainian missiles in the Kerch Strait area."
"The Crimean bridge is not damaged," he said, urging people to remain calm and trust only official sources of information.

Meanwhile, Russian state media outlet RIA Novosti said that the country's special services had installed a "smokescreen" by the bridge and that "traffic will resume soon."
Moscow blamed Kyiv in July for attacking the bridge following explosions on the 12-mile-long structure which was also sabotaged last October.
In reposting Saturday's video, Ukrainian internal affairs adviser Anton Gerashchenko noted "for the first time events on the Kerch Bridge are taking place in the daytime."
This is Kerch Strait bridge today. There are reports of explosions near the bridge, potentially Russian air defence attempting to intercept incoming UAVs or missiles:
— Alex Kokcharov (@AlexKokcharov) August 12, 2023
pic.twitter.com/q4Tmh1JdaA
Social media users said that both the rail and road bridge had probably been struck several times by multiple drones, although there was no confirmation of this. "The Kerch bridge right now. It's going to go down as a military logistics facility sooner or later," tweeted Ukrainian journalist Illia Ponomarenko next to the video.
Pro-Ukrainian user Margo Gontar posted video showing beachgoers viewing the smoke billowing into the sky, writing, "special hit this summer in Crimea: swimming with a view on a burning Kerch bridge."
The Russian Defense Ministry said in a statement on Telegram that Ukraine had attempted a "terrorist strike" on the bridge using an S-200 anti-aircraft guided missile. "The Ukrainian missile was detected in time and intercepted in the air by Russian air defense systems," it said.
Russian authorities played down reports that it had been damaged and said that traffic was only temporarily stopped.
Newsweek has contacted the Ukrainian Defense Ministry for comment. Kyiv has celebrated but not directly claimed responsibility for previous strikes on Russian targets, including in Crimea.
On July 17, Moscow said Ukraine had attacked the bridge with two drones in what it described as a "terrorist attack" which damaged the road part of the structure and killed two people. There was considerable damage to the bridge last October when a truck was blown up, igniting train tankers carrying fuel.
The bridge is a key supply line for Russian troops in their full-scale invasion and is also considered by Ukraine as a symbol of occupation of the peninsula that President Vladimir Putin illegally annexed in 2014.
Update 8/12/2023, 7:45 a.m. EDT: This article was updated with more information.