A blast on the strategic road-and-rail bridge linking Russia and the Crimea peninsula on Saturday brought down sections of road taking traffic in one direction, prompting gleeful messages from Ukrainian officials but no direct claim of responsibility.
Russia seized Crimea from Ukraine in 2014 and the 19-kilometre bridge linking it to Russia’s transport network was opened with great fanfare by President Vladimir Putin four years later.
It now represents a crucial supply route for the Russian forces who .
The Russian National Anti-Terrorism Committee said on social media that the blast occurred at 6:07am (2:07pm AEDT) in a freight truck, and caused seven fuel tanker wagons to catch fire on a train heading for the peninsula.
The Kerch bridge pictured in 2018. It is a crucial supply route for the Russian forces who have taken control of most of southern Ukraine's Kherson region. Source: AAP / AP
Local officials said later that it had reopened to motor traffic with vehicles subject to stringent screening. Shortly after, Grand Service Express, which operates rail services there, said the first trains had left the peninsula for Moscow and St Petersburg.
Images showed thick smoke pouring from part of the bridge.
Later, the Emergency Ministry said the fire had been extinguished, the Russian news agency Interfax reported.
A Ukrainian presidential adviser posted a message on Twitter saying the incident was just "the beginning" but stopped short of saying Ukrainian forces were responsible for the blast.
"Everything illegal must be destroyed, everything that is stolen must be returned to Ukraine, everything occupied by Russia must be expelled," Mykhailo Podolyak wrote.
But in a later statement, he appeared to suggest that Moscow had a hand in the blast.
"It is worth noting that the truck that detonated, according to all indications, entered the bridge from the Russian side. So the answers should be sought in Russia," he said.
The Ukrainian post office announced it was preparing to print stamps showing the "Crimean bridge — or more precisely, what remains of it".
Russia says three killed in the blast, army leadership changed
Russian investigators said on Saturday that three people had been killed, without immediately blaming Ukraine.
The bodies of an unidentified man and a woman were pulled out of the water, likely passengers in a car driving near the exploded truck, Moscow said.
The authorities also said they had identified the owner of the truck as a resident of Russia's southern Krasnodar region, saying his home was being searched.
On the same day, after a series of setbacks on the battlefield that triggered unprecedented criticism of its army at home, Moscow appointed a new general to lead its Ukraine offensive.
Mr Putin has instructed the government to create a state commission to investigate the incident, TASS news agency reported, citing Kremlin spokesman Dmitry Peskov.
Interfax quoted the chairman of the Crimean republic's State Council, Vladimir Konstantinov, as saying that "Ukrainian vandals managed to reach for the Crimean bridge with their bloody hands".
"They now have something to be proud of," he said. "In their 23 years of economic activity they failed to build anything worthy of attention in Crimea, but (now) they have managed to damage the roadway of the Russian bridge."
Mr Konstantinov said the damage was "not of a severe nature" and would be quickly repaired.
The head of Ukraine's National Security and Defence Council, Oleksiy Danilov posted a video of the burning bridge on social media alongside a video of Marilyn Monroe singing "Happy birthday, Mr President".