According to CNN:
A Ukrainian security official has claimed Kyiv’s responsibility for an attack on the bridge linking the annexed Crimean peninsula to the Russian mainland – a vital supply line for Russia’s war effort in Ukraine and a personal project for President Vladimir Putin.
The nearly 12-mile crossing, also known as the Kerch Bridge, is the longest in Europe and holds huge strategic and symbolic importance for Moscow. Monday’s attack on the bridge was the second since Russia launched its invasion of Ukraine, after a fuel tanker exploded while crossing it in October.
A source in Ukraine’s Security Service (SBU) told CNN this attack was a joint operation of the SBU and Ukraine’s naval forces. The source spoke on condition of anonymity because they had not received authorization to speak on the record.