The latest incidents followed huge blasts last week at an air base in Russian-annexed Crimea.

In a new assessment, a Western official said that incident had rendered half of Russia's Black Sea naval aviation force useless in a stroke.

Russia's RIA and Tass news agencies, citing a local official in Crimea, said it appeared Russian anti-aircraft forces had been in action near the western Crimean port of Yevpatoriya on Friday night.

Video posted by a Russian website showed what appeared to be a ground-to-air missile hitting a target. Reuters was unable to confirm the video's veracity.

Tass cited a local official as saying Russian anti-aircraft forces knocked down six Ukrainian drones sent to attack the town of Nova Kakhovka, east of the city of Kherson.

Ukraine says retaking Kherson is one of its main priorities.

"The Ukrainian armed forces treated the Russians to a magical evening," Seriy Khlan, a member of Kherson's regional council disbanded by Russian occupation forces, said.

The night before, multiple explosions had been reported in Crimea - which Moscow seized in 2014 - including near Sevastopol, headquarters of Russia's Black Sea Fleet, as well as at Kerch near a huge bridge to Russia.

Inside Russia, two villages had been evacuated after explosions at an ammunition dump in Belgorod province, more than 100km from territory controlled by Ukrainian forces.

Kyiv has been withholding official comment on incidents in Crimea or inside Russia while hinting it is behind them using long-range weapons or sabotage.

Huge explosions on August 9 at Russia's Saky air base on the Crimean coast had put more than half of the Black Sea Fleet's combat jets out of use, a Western official said, in what would be one of the costliest attacks of the war.

Russia has denied aircraft were damaged in what it called an accident, although satellite pictures showed at least eight burnt-out planes and several huge craters.

Moscow this week dismissed the head of its Black Sea Fleet.

Ukraine hopes its apparent new-found ability to hit Russian targets behind the front line can turn the tide in the conflict, disrupting the supply lines Moscow needs to support its occupation.

A senior US defence official said on Friday US President Joe Biden's administration was preparing another security assistance package for Ukraine valued at $US775 million ($A1.1 billion) and containing surveillance drones and, for the first time, mine-resistant vehicles.

A senior Ukrainian official said around half of incidents reported in Crimea were Ukrainian attacks, and half were accidents caused by Russia's poor operations.

He emphasised attacks were carried out by saboteurs rather than long-range weapons.

The official, who declined to be named, said Ukraine had hoped its strikes would have a bigger impact in reducing Russian artillery power but Moscow was adapting.

Ukraine also issued dire warnings about a frontline nuclear power station, the Zaporizhzhia complex, where it said it believed Moscow was planning a "large-scale provocation" as justification to decouple the plant from the Ukrainian power grid and connect it to Russia's.

"If the Russian blackmail with radiation continues, this summer may go down in the history of various European nations as one of the most tragic of all time," Ukrainian President Volodymyr Zelenskiy said in an address Friday evening.

"Because no nuclear power station anywhere in the world has a procedure for a terrorist state turning (it) into a target."

Continuing the mutual blame game, Russian President Vladimir Putin accused Ukraine of shelling the complex, risking a nuclear catastrophe.

Moscow has rejected international calls to demilitarise the plant and Putin on Friday renewed his accusation that Kyiv was shelling it in a phone call with French President Emmanuel Macron, according to the Kremlin's readout.

Macron's office said Putin agreed to a mission to Zaporizhzhia by the International Atomic Energy Agency.

Australian Associated Press