A drone attack on an ammunition depot in Crimea has led to civilian evacuations and disrupted transport, Russian authorities have said.
Sergei Aksyonov, the Russian-installed governor of occupied Crimea, said Ukraine was behind the attack, without providing evidence.
Mr Aksyonov said local residents living within five kilometres of the blast were being evacuated.
Rail services across the Kerch bridge have also reportedly been halted.
Earlier on Saturday, Russian authorities stopped traffic on the bridge, but then swiftly reopened it to cars.
A later update from the Moscow-installed government said road traffic was again halted until further notice.
Mr Aksyonov said infrastructure facilities in the Krasnogvardeysky district in Crimea were the target.
"According to preliminary data, there were no damages or casualties," Mr Aksyonov wrote on a Telegram post.
The BBC has not been able to independently verify the attack.
The Kerch bridge, often referred to as the Crimea bridge, was opened in 2018 and it enables road and rail access between Russia and Crimea - Ukrainian territory annexed by Russia in 2014.
The bridge has become a symbol of Russian occupation and is also an important re-supply route for Russian forces in southern Ukraine.
On Monday, a blast on the bridge killed two people and damaged the road but the railway line, which runs parallel to it, was not damaged.
The Kremlin blamed Kyiv 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 "cruel" attack.
Ukrainian President Volodymyr Zelensky has said the Crimea bridge is a legitimate target.
Speaking on Friday he said the bridge was "the route used to feed the war with ammunition and this is being done on a daily basis", adding that Kyiv sees it as "an enemy facility".
"So, understandably, this is a target for us," Mr 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 huge explosion. It was fully reopened in February.
It was called by putin the safest structure on the planet that is protected by 20 different systems.
This bridge not only is important for the military, but also for putin's ego.
Why Ukraine didn't attack it earlier? According to Russia they shouldn't be able to attack it now.
Anyway if the bridge falls, Russia would be able to supply soldiers only via eastern routes, which all are now under artillery range.
They did attack it earlier. The earlier attack put the rail lines out of commission for a bit and managed to get the road down to a single lane. Then it was repaired. Russia has air superiority in that area. They are not so good at catching remote operated (autonomous?) boat bombs.