Ukraine and Russia accused each other of overnight drone attacks hours after Russian President Vladimir Putin vowed revenge for a strike that damaged his flagship bridge to Crimea.

Russia’s Defense Ministry said 28 Ukrainian drones attempted to attack facilities in Crimea, one of the most intense drone strikes against the peninsula since the war began. All the unmanned aerial vehicles were repelled and there were no reports of damage or injuries, according to a statement on the ministry’s Telegram channel.

Ukrainian officials said they downed a total of 31 drones in the southern regions of Odesa and Mykolayiv and also intercepted six Kalibr missiles launched from the Black Sea. An industrial facility in the southern Mykolayiv region was hit during the Russian attacks and debris from one of the intercepted missiles damaged port infrastructure facilities in Odesa, regional officials said.

The attacks happened hours after Putin on Monday threatened to strike at Ukraine in retaliation for explosions that damaged Russia’s 19-kilometer (12-mile) bridge connecting Russia to Crimea across the Kerch Strait, the most serious attack against the roadway since a massive blast in October. Ukraine didn’t directly claim involvement.

With one of the bridge’s two dual-lane highways damaged by the explosions, road traffic between Russia and Crimea resumed Tuesday along the other span. Vehicles were crossing in single file in each direction, the Interfax news service reported, citing Russian Deputy Prime Minister Marat Khusnullin.

Rail transport, which was also interrupted by the blasts, resumed later Monday.

The bridge strikes occurred hours before Russia announced it was halting a deal permitting Black Sea grain exports from Ukraine nearly a year into the agreement brokered by the United Nations and Turkey. The move heightened uncertainty over global food supplies, but Kremlin spokesman Dmitry Peskov said the decision was unrelated to the bridge incident. Russia repeatedly indicated it was likely to withdraw from the agreement.

Putin called construction of the bridge a “historical mission” for Russia before it opened in 2018, four years after he annexed Crimea from Ukraine. After the October strike on the bridge, Russia unleashed some of the most intense barrages of attacks against Ukraine since the first days of its February 2022 invasion.

(Updates with Russia resuming road traffic on bridge in fifth paragraph)