Russian authorities say a drone strike on an ammunition depot in Crimea has forced the evacuation of civilians and disrupted traffic.
Sergei Aksyonov, the governor of Russian-occupied Crimea, said Ukraine was behind the attack without providing evidence.
Aksyonov said local residents living within five kilometers of the blast had been evacuated.
Rail services across the Kerch Bridge have also been suspended.
Earlier on Saturday, Russian authorities stopped traffic on the bridge, but quickly reopened it to cars.
A later update from the government installed by Moscow said road traffic was again halted until further notice.
Aksyonov said the infrastructure in the Krasnogvardeysky district in Crimea was the target.
The BBC was unable to independently verify the attack.
The Kerch Bridge, commonly known as the Crimean Bridge, opened in 2018, allowing road and rail access between Russia and Crimea, a Ukrainian territory annexed by Russia in 2014.
The bridge has become a symbol of the Russian occupation and also an important resupply route for Russian forces in southern Ukraine.
On Monday, an explosion on the bridge killed two people and damaged the road, but the railway running parallel to it was undamaged.
The Kremlin blamed Kiev for Monday’s attack and said Ukraine had carried out a “terrorist” act. Russian President Vladimir Putin vowed to retaliate and accused Ukraine of launching a “senseless” and “heinous” attack.
Ukrainian President Volodymyr Zelensky said the Crimean bridge was a legitimate target.
Speaking on Friday, he spoke of the need to “neutralize” the bridge, explaining that it was “a road used to supply ammunition for war and this was done on a daily basis” and Kyiv considered it an “enemy base”.
“So, understandably, this is our goal,” Zelensky said in a video address to the Aspen security conference in the US.
Monday’s alleged attack was the second major incident on the Kerch Bridge in the past year.
In October 2022, the bridge was partially closed following a massive explosion. It was fully reopened in February.