Moscow - (AFP) - The Kremlin-appointed authorities of the Kherson region in southern Ukraine announced Thursday that electricity was fully restored to its largest city, after blaming Kiev for attacks that disrupted power and water supplies.

Kherson was the first urban center captured by Russian forces after Moscow announced the start of a "special military operation" in Ukraine in February and suffered power outages after Sunday's strikes, for which Moscow and Kiev blame each other.

"The electricity is available, despite the vandalism and attacks," the Kremlin-appointed deputy head of the Kherson region, Yarel Strimosov, said on social media Tuesday.

Ukrainian forces have been advancing towards the city for months, and Kiev's control over it would be a major defeat for Moscow.

Sunday's news of the power outage followed reports from Russian officials that the Khakova dam in Kherson had been damaged in a Ukrainian strike.

The dam supplies water to Crimea, which was annexed by Moscow in 2014 and used to launch the military campaign in Ukraine.

Separately, the Russian security services (FSB) announced the arrest of nine members of an "intelligence and sabotage group" of the Ukrainian forces.

The FSB accused the group of planning attacks against high-ranking Russian-appointed officials operating in Kherson.

It reported the confiscation of explosives, bombs and ammunition during the arrests, announcing the opening of an investigation related to "international terrorism".

As Ukraine presses forward with its counteroffensive in the south, Moscow's forces have declared that they will turn Kherson into a "fortress".

For weeks, it organized withdrawals of civilians from the Kherson region in light of the advance of Ukrainian soldiers, which Kiev described as "deportations".