A blast on the strategic road-and-rail bridge linking Russia and the Crimean peninsula on Saturday brought down sections of road taking traffic in one direction, damaging a crucial supply route for Russian forces in Ukraine.
A large fire on the only crossing between the occupied Crimean peninsula and Russia was caused by a lorry explosion, Russian officials say.
A blast on the road section led to oil tankers on the rail section catching fire, before the road collapsed.
Crimea was annexed in 2014 by Russia, which now uses the bridge to move military equipment into Ukraine.
The official Twitter account of the Ukraine government responded to the fire by tweeting: “Sick burn.”
An adviser to Ukraine’s President Zelensky, Mykhailo Podolyak, did not directly claim Ukrainian responsibility, but wrote: “Crimea, the bridge, the beginning.
“Everything illegal must be destroyed, everything stolen must be returned to Ukraine, everything occupied by Russia must be expelled.”
Russia’s National Anti-Terrorism Committee said: “At 06:07 Moscow time today [03:07 GMT], an explosion was set off at a cargo vehicle on the motorway part of the Crimean bridge on the side of the Taman peninsula, which set fire to seven fuel tanks of a train that was en route to the Crimean peninsula.
“Two motorway sections of the bridge partially collapsed.”
Crimean parliamentary speaker Vladimir Konstantinov blamed the explosion on “Ukrainian vandals, who have finally managed to reach their bloody hands to the Crimean bridge”.
He added the damage to the bridge would be “promptly restored, since it is not of a serious nature”.