MOSCOW - Ukrainian shelling badly damaged the crucial Antonivskyi bridge in the Russia-controlled Kherson region of southern Ukraine, Moscow-installed regional authorities said on Wednesday.

The bridge - one of only two crossing points for Russian forces to territory they have occupied on the western bank of the vast Dnipro river in southern Ukraine - has been a key target for Ukrainian forces in recent days, with Kyiv using high-precision U.S.-supplied rockets to try to destroy it.

The Russian-backed head of the Kherson region, Volodymyr Saldo, closed the bridge to cargo traffic on Wednesday morning in what he called a "temporary restriction" to allow repair works.

Passenger cars were still able to use the bridge, which is more than a kilometre long, Saldo said in an "urgent appeal" published on social media.

Local officials told the RIA news agency that Ukraine hit the bridge at around 4:00 a.m. with 12 shells from the newly arrived High Mobility Artillery Rocket Systems (HIMARS), a U.S. supplied long-range artillery weapon which Kyiv hopes will turn the tide of the war.

"If the strikes continue, the bridge might collapse," the TASS news agency quoted the deputy head of the Russian-installed administration as saying.

Britain's defence ministry described the bridge as a "key vulnerability for Russian forces".

"It is one of only two road crossing points over the Dnipro by which Russia can supply or withdraw its forces in the territory it has occupied west of the river," it said in a daily intelligence briefing.

Territory occupied by Russian forces on the western side of the river include the region's main city, Kherson, home to 280,000 people before Russia's Feb. 24 invasion.

Russia captured the city and most of the surrounding area with little resistance in the early days of the invasion, but Ukrainian officials have in recent weeks talked up a planned counter-offensive, backed by Western-supplied weapons, to retake the territory.

(Editing by Andrew Heavens and Catherine Evans)