Russia is deploying defensive measures, including smoke generators and underwater barriers, to reduce the risk of attacks on the Kerch Bridge, according to intelligence from the UK Ministry of Defence (MOD).
The bridge, also known as the Crimea Bridge, connects mainland Russia to the Russian-occupied Crimean peninsula.
According to the MOD Russia is heavily reliant on the bridge and ferries to cross the Kerch Strait to reach Russian forces in south-eastern Ukraine.
"The Kerch Strait is a bottleneck for military logistics support to Russian forces in occupied areas of Kherson and Zaporizhzhia Oblasts," the MOD intel report said.
"Russia is employing a range of passive defences such as smoke generators and underwater barriers, alongside active defence measures such as air defence systems, to strengthen the survivability of water crossings and minimise damage from future attacks."
The bridge has sustained several attacks in the past 10 months but has not been completely severed.
It is critically important for logistics and is a symbol of Russian occupation and pride.
According to the MOD, as of August 29, imagery confirms Russia has created an underwater barrier of submerged ships and containment booms to protect against Uncrewed Surface Vehicle (USV) attacks against the bridge.
At the southern part of the bridge, this includes several vessels 160 metres apart. These are located at the same place as the Ukrainian "Sea Baby" USV attacks on 17 July 2023.
A USV, also referred to as a boat drone or sea drone, is a watercraft that operates on the surface of the water without requiring a crew.
Additional countermeasures employed to safeguard the bridge involve the use of TDA-3 truck-mounted smoke generators, as demonstrated during an exercise on May 24, 2023.
This smoke was subsequently activated on August 12, 2023, as a deterrent against potential airborne threats.
To deter radar-seeking missiles, the Russian Navy also briefly tried using radar decoys on barges for several days in September 2022, the MOD said.
Earlier in the month Ukraine released footage of their boat drone damaging a Russian Navy Landing Ship at a naval base in Novorossiysk.