Russian President Vladimir Putin has vowed to retaliate after a Ukrainian attack on a bridge linking Moscow-annexed Crimea to Russia killed two civilians.
"Of course, there will be a response from Russia. The defence ministry is preparing relevant proposals," he said in televised remarks.
A Russian couple were killed and their 14-year-old daughter wounded as they drove across the Crimean Bridge at night for what they hoped would be a family holiday on Crimea's Black Sea coast.
It was not immediately clear how the bridge, one of Mr Putin's prestige projects, was attacked but video posted on social media showed the family's car in ruins. As other drivers try to give assistance, a girl can be heard crying and whimpering.
The girl was named as 14-year-old Angelina. Her parents, Alexei and Nataliya, both died.
"The girl was injured," Vyacheslav Gladkov, governor of the Belgorod region, said on the Telegram messaging app.
"The hardest thing is that her parents died - dad and mum. No words can soothe the pain of loss here," he said.
The car they had been travelling in was from the Belgorod region, one of the Russian border regions that has seen the conflict in neighbouring Ukraine spill across the frontier.
Russia's Investigative Committee said Kyiv was behind the attack and opened a terrorism case.
Ukraine's military suggested Russia was responsible but Ukrainian media said Ukrainian security services had used underwater drones to attack the bridge, which had only recently returned to full operation after suffering severe damage in a similar attack last October.
The girl sustained injuries to her head and chest but was conscious and breathing independently and her life was not in danger, according to the local emergency response headquarters, which said psychologists were on hand.
Russian media said the family had been on their way to a holiday in Crimea, which Russia seized and unilaterally annexed from Ukraine in 2014.
Earlier Russian officials said the Crimea Bridge - a key supply line for Russian troops in Ukraine - was damaged following an "emergency" situation, and suspended traffic.
The 19km road and rail bridge has been a pride infrastructure project of President Vladimir Putin, who drove a Mercedes across the bridge in 2022 after it was repaired following an explosion.
Sergei Aksyonov, a Russia-installed governor, said the emergency occurred on the 145th pillar of the bridge which links the Crimean peninsula to the Russian region of Krasnodar.
Russia's transport ministry said that there was damage to the road on the bridge closer to the Crimean Peninsula, but there was no damage to the pillars. It did not say what caused the damage.
The RBC-Ukraine news agency reported that explosions were heard on the bridge.
Russia's Grey Zone channel, a heavily followed Telegram channel affiliated with the Wagner mercenary group, reported that there were two strikes on the bridge at 3.04am and 3.20am.
Read more:
Crimea bridge: Why is it important and what happened to it?
George Barros, an analyst at the Washington-based Institute for the Study of War, said on Twitter that if the bridge was seriously damaged it would significantly impact Russian supply lines.
"Russia will only have one ground supply line - the coastal highway on the Sea of Azov - to sustain (or evacuate) its tens of thousands of troops in occupied Kherson & Crimea if UKR manages to degrade/destroy the bridge," Mr Barros said.
Hours after the attack, Russia said that it was halting participation in a landmark UN-brokered deal which allowed Ukrainian grain to be exported through the Black Sea.
The UN deal is due to expire today, with the last ship to travel under the deal leaving the port of Odesa early yesterday, according to a Reuters witness and MarineTraffic.com.
The Crimean Bridge was damaged by an explosion last October, in an attack that the Kremlin said had been orchestrated by Ukrainian security forces. Ukraine admitted only indirectly to the attack months later.
Mr Putin's ally Arkady Rotenberg's company built the vast structure, which is Europe's longest bridge. Mr Putin has long lauded the project, boasting at one point that Russian Tsars and Soviet leaders had dreamed of building it but never did.
The Crimean peninsula has been a major and cherished holiday destination for Russians, especially after Moscow launched its invasion on Ukraine in 2022 and travelling to the West became more difficult for many Russians.
In recent weeks, traffic jams to the entrance of the bridge went for kilometres on a daily basis as Russians went on holidays.
This morning the traffic jam ran for kilometres before police directed vehicles away from the bridge. Social media accounts showed cars lined up on the bridge and its entrance.
The Russian-backed administration of the Crimean peninsula urged residents not to travel via the bridge.
