(Reuters) - Russia's Defence Ministry said early on Saturday that its forces had destroyed an unmanned Ukrainian boat being used in an attempt to attack the bridge linking the Crimean peninsula to the Russian mainland.

The bridge, completed in 2018, four years after Russia occupied and annexed the peninsula from Ukraine, has come under repeated attack in Moscow's 18-month-old full-scale invasion of its neighbour.

"On 1st September at about 11.15 p.m. (2015 GMT), an attempt was undertaken by the Kyiv regime to launch a terrorist strike with a half-loaded unmanned boat," the ministry said on Telegram.

It said the boat had been "spotted and destroyed in time off the Black Sea coast".

There was no immediate comment from Ukrainian officials, who normally say little or nothing about attacks on Russian targets but say that destroying Russian infrastructure is vital for the country's war effort.

Ukraine claimed responsibility for an attack in July on the bridge by what has been described as a sea drone. Two people died in that incident.

The 19-km (12-mile) bridge across the Kerch Strait was badly damaged in October 2022 in an explosion that Russian officials said was caused by a truck that blew up while crossing the bridge.

(Reporting by Reuters; Editing by Ron Popeski and Leslie Adler)