Moscow announced on Saturday that a truck blast ignited a huge fire and severely damaged the Kerch Key Bridge – built as Russia’s only land link with annexed Crimea – and vowed to find the culprits without immediately blaming Ukraine give.

Russia said the blast set fire to seven oil tankers being transported by train and collapsed two car lanes of the giant road and rail structure.

Dramatic social media footage showed the bridge on fire, with parts falling into the water.

“Today at 06:07 (0307 GMT) on the road side of the Crimean bridge … a car bomb exploded and set fire to seven oil tankers being transported to Crimea by rail,” Russian news agencies quoted the national anti-terrorist committee as saying.

The bridge, which was personally inaugurated by President Vladimir Putin in 2018, is a key transport link for bringing military equipment to Russian soldiers fighting in Ukraine.

It is hugely important to the Kremlin and Moscow had claimed the bridge crossing was safe despite the fighting.

Ukrainian Presidential Advisor Mykhailo Podolyak previously posted a picture of a long stretch of the half-submerged bridge on Twitter.

“Crimea, the bridge, the beginning,” he wrote.

“Everything illegal must be destroyed, everything stolen must be returned to Ukraine, everything occupied by Russia must be expelled.”

The Post of Ukraine announced that it is preparing to print postage stamps depicting the “Crimean Bridge – or, more precisely, what remains of it”.

The Kremlin spokesman said Putin had ordered a commission to be set up to investigate the blast, Russian news agencies reported.

Russia’s powerful investigative committee launched a criminal investigation into the blast and dispatched detectives to the scene.

It said a truck exploded “on the automobile part of the Crimean bridge from the Taman Peninsula side.”

This “resulted in seven fuel tanks igniting on a train bound for Crimea. As a result, two lanes partially collapsed.”

Officials in Moscow stopped blaming Kyiv.

But an official in Russia-set up Crimea pointed the finger at “Ukrainian vandals.” Another in the neighboring Kherson region said repairs could “take two months”.

And the Russian Foreign Ministry spokeswoman said Kiev’s response to the blasts showed its “terrorist character.”

“There is a blatant war of terror against us,” Russia’s ruling party MP Oleg Morozov told RIA Novosti news agency.

“If we remain silent and don’t respond appropriately, such attacks will multiply,” he said.

There have been several explosions at Russian military installations on the Crimean peninsula.

If Ukraine turns out to be behind the latest blast, alarm bells could ring with the bridge being so far from the frontline.

The blasts come after Ukraine’s recent lightning-fast territorial gains in the east and south, which have undermined the Kremlin’s claims that it annexed Donetsk, neighboring Lugansk and the southern regions of Zaporizhia and Kherson.

Moscow-installed head of the peninsula, Sergei Aksyonov, urged Crimea to “remain calm” as authorities appeared to downplay the blasts.

“I urge everyone to hold back and not spread fake information,” he said on Telegram. “The situation is being controlled, professionals are working on site.”

He said rail services to Russia had been suspended, adding that authorities had set up food and heating points to help stranded drivers.

Authorities were also trying to allay fears of food and fuel shortages in Crimea, which has been entirely dependent on mainland Russia since its annexation by Moscow in 2014.

Russia’s Transport Ministry said a ferry service had been launched. The Department of Energy told authorities that the peninsula was fully fueled.

The blasts came a day after President Vladimir Putin’s 70th birthday.

Russian forces on Friday said they had seized ground in Donetsk in eastern Ukraine, their first claim of fresh gains since a Kiev counter-offensive rocked Moscow’s war effort.

Separatist forces in the war-torn Donetsk region said they have retaken a number of villages near the Ukrainian-controlled industrial town of Bakhmut, which has been under Russian shelling for weeks.

The Donetsk region, which has been partially controlled by Kremlin-backed separatists for years, is a key win for Russian forces, which deployed troops to Ukraine in February.

But Kiev’s forces have pushed back Russian soldiers across frontlines in the south and east, including parts of Donetsk, in recent weeks.

Ukrainian President Volodymyr Zelenskyy said late Friday his forces had retaken nearly 2,500 square kilometers (965 sq mi) in the counteroffensive that began late last month.

Zelensky has urged punishing Russia in other areas and urged Brussels to step up pressure on its energy sector – a day after the EU imposed a new round of sanctions on Moscow.

In the more than seven months since the Russian offensive, Putin has made thinly veiled threats to use nuclear weapons.

US President Joe Biden warned Thursday the world is facing “Armageddon” as Putin could deploy his nuclear arsenal.

But on Friday, the White House turned the alarm down and said the president’s comments did not reflect any new information.