Pre-dawn explosions hit the only bridge linking the occupied Crimea Peninsula to mainland Russia on Monday, damaging a key symbol of President Vladimir V. Putin’s claims to sovereignty over Ukrainian territory and briefly disrupting a vital supply line to Russian troops.
The explosions were the second time the Kerch Strait was hit in 10 months. And while these caused far less damage than an explosives-laden truck that exploded last October, they exposed the vulnerability of the bridge – and other Russian supply routes far from the front – as Ukraine mounts a tense counter-offensive to reclaim ground.
Russia on Monday accused Ukraine of using naval drones to attack the bridge, a strategic link for Russian forces fighting in southern Ukraine. Ukrainian officials celebrated the attack, but neither claimed nor denied responsibility for the blasts.
Hours after the attack, Moscow announced it was withdrawing from the Black Sea grain agreement, a deal that allowed Ukraine to export its grain by sea despite Moscow’s naval blockade. Dmitri S. Peskov, a Kremlin spokesman, said the bridge attack was unrelated to Russia’s decision to suspend its participation in the agreement, which has helped keep global food prices stable.
Rail service over the bridge resumed Monday morning. But damage to the highways, which apparently left part of the road bowing, according to a video verified by The New York Times, threatened to curtail Russian logistics operations.
If the bridge were destroyed or seriously damaged, Moscow would be left with a single major land route from Russia, along Ukraine’s southern coast, to support tens of thousands of troops fighting to hold on to territory captured in the first weeks of its invasion.
Mr Putin, in a meeting with transport officials broadcast on state television, condemned the explosions as “another terrorist attack carried out by the Kyiv regime.” He said the Defense Ministry was preparing Russia’s response and that Russia’s main security service, the FSB, would investigate.
“Considering that this is the second terrorist attack on the Crimean bridge,” Mr. Putin said, “I await concrete proposals to improve the security of this strategically important transportation facility.”
One bridge segment was destroyed, and another was dislocated by more than 30 inches, according to Marat Khusnullin, Russia’s deputy prime minister. But the main pillars of support remained intact, which Mr Putin called “good news”.
Mr. Khusnullin said limited vehicle traffic could resume as soon as Tuesday. Less damaged lanes would be restored by mid-September, and the rest of the lanes by November, he said.
Pro-military Russian military bloggers and commentators described the attack, which officials said killed two people and wounded a third, as evidence of another failure by the Russian military command. Igor Girkin, a former Russian intelligence officer who runs a prominent blog, said Ukraine will strike again and again until the bridge link is severed.
The attack came as Ukrainian forces were engaged in a grinding counteroffensive, now five weeks old, aimed at driving Russian forces out of areas of southern and eastern Ukraine. Russian troops are dug in behind fields laden with mines, so the Ukrainian military has been forced to move cautiously and progress has been slow.
Isolating Russian forces in Crimea is a vital part of the Ukrainian counter-offensive strategy, according to analysts. Ukrainian ground forces have sought to drive a wedge through the natural land bridge that connects Russia to the peninsula through southern Ukraine, and have repeatedly targeted the bridge, which Mr. Putin ordered built after Russia illegally annexed Crimea in 2014.
When the bridge opened in 2018, Mr Putin hailed it as a “remarkable” achievement that strengthened Crimea. With its opening, he said, “we are all even closer to each other.”
The explosion that hit the bridge last October was large enough to rupture fuel tanks from a passing train, setting it on fire, and pulled part of the road from its joints and into the sea. Ukrainian officials did not acknowledge any role until months later, but called the 12-mile bridge a legitimate military target because of its crucial logistical role in the Kremlin’s war effort.
“All illegal structures used to deliver Russian instruments of mass murder are necessarily short-lived, regardless of the reasons for the destruction,” Mykhailo Podolyak, a senior adviser to President Volodymyr Zelensky of Ukraine, said on Twitter on monday
After the October attack, Moscow intensified countermeasures to defend the structure, deploying a ship with a set of radar reflectors to protect the bridge.
A Russian agency, the National Anti-Terrorism Committee, said in a statement that Ukraine attacked the bridge on Monday with two naval drones, a claim that cannot be independently verified. Video and photos verified by The Times showed the most significant damage along a span of the bridge heading toward Russia. One photo also showed a damaged car on the bridge.
Although demolishing a bridge in wartime has historically been difficult, air and water drones can provide new ways to target the weakest points.
“Precision-guided weapons, where you can hit a specific part of the bridge, make it less difficult to hit,” said Samuel J. Cox, a retired rear admiral and the director of the Naval History and Heritage Command in Washington. “That allows you to get to a specific point on the bridge where you can do more damage.”
But bridge designs have improved over the years, meaning that a bridge often retains the structural integrity to be repaired, instead of having to be replaced.
“I would think the Russians could fix this pretty quickly,” Admiral Cox said.
Milana Mazaeva, Ivan Nechepurenko, James Glanz and Axel Boada contributed reporting.