Russia condemned remarks by Ukrainian officials on Saturday's explosion on the strategic bridge in Crimea, saying they testified to Kyiv's "terrorist nature."
"The reaction of the Kyiv regime to the destruction of civilian infrastructure testifies to its terrorist nature," Foreign Ministry spokeswoman Maria Zakharova said on Telegram.
The Kerch Bridge -- a pair of parallel bridges, one road and one railroad -- is a key supply route for Russia which was built after Crimea was annexed in 2014.
Early Saturday, a huge explosion followed by a fire caused a road section on the bridge to collapse and set several train carriages ablaze.
The fire was extinguished later in the day, Russian authorities said, confirming no casualties were reported.
'Just the beginning'
Although Ukraine did not directly claim responsibility for the attack, multiple statements by top Ukrainian officials pointed to the possibility.
Ukraine's senior presidential adviser Mykhailo Podolyak said what happened on the bridge is just "the beginning."
"Everything illegal must be destroyed, everything stolen must be returned to Ukraine, everything occupied by Russia must be expelled," Podolyak said in a tweet.
Ukraine's National Security and Defense Council Secretary Oleksiy Danilov shared a video split in two parts, with one side displaying the fire on the bridge and the other side playing Marilyn Monroe's famous "Happy Birthday Mr. President" song.
"Putin should be happy. Not everyone gets such an expensive present on their birthday," a Ukrainian official told the New York Times speaking on the condition of anonymity.
On Friday, Russian President Vladimir Putin turned 70.