Ukrainian authorities have claimed a measure of success over Russia’s use of Iranian drones, while the Kremlin’s talk of a possible “dirty bomb” attack has added another worrying dimension as the war enters its ninth month.

Ukrainians are bracing for less electric power this winter following a sustained Russian barrage on the country’s infrastructure in recent weeks. Citizens in the southern Ukrainian city of Mykolaiv lined up for water and essential supplies as Ukrainian forces continued their advance on the nearby Russian-occupied city of Kherson.

Ukraine’s forces have shot down more than two-thirds of the approximately 330 Shahed drones that Russia has fired at the country, the head of Ukraine’s intelligence service, Kyrylo Budanov, said. Budanov said Russia’s military had ordered about 1700 various types of drones and is rolling out a second batch of about 300 Shaheds.

“Terror with the use of Shaheds can actually last for a long time,” he was quoted as saying in Ukrainska Pravda newspaper, adding: “Air defence is basically coping, 70 per cent are shot down.”

Both Russia and Iran deny that any Iranian-built drones have been used in the war but the triangle-shaped Shahed-136s have rained down on civilians in Kyiv and elsewhere in Ukraine.

Police block a square after a drone fired on buildings in Kyiv. Photo / Efrem Lukatsky, AP

Britain’s Ministry of Defence, in an intelligence update on Twitter, said Russia was likely to use a large number the drones to try to penetrate “increasingly effective Ukrainian air defences” - in part to substitute for Russian-made long-range precision weapons “which are becoming increasingly scarce”.

That assessment came on top of a stark warning by Russian Defence Minister Sergei Shoigu to key British, French, Turkish, and US counterparts over the weekend that Ukrainian forces were preparing a “provocation” involving a radioactive device - a so-called “dirty bomb”. Britain, France, and the United States rejected that claim as “transparently false”.

A dirty bomb uses explosives to scatter radioactive waste in an effort to sow terror. Such weapons don’t have the devastating destruction of a nuclear explosion but could expose broad areas to radioactive contamination.

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Russian authorities subsequently doubled down on Shoigu’s warning.

Lt General Igor Kirillov, head of the Russian military’s radiation, chemical, and biological protection forces, said Russian military assets were on high readiness for possible radioactive contamination. He told reporters a “dirty bomb” blast could contaminate thousands of square kilometres and spew deadly radiation up to 1500km.

Medics help injured woman after a drone fired on buildings in Kyiv. Photo / Efrem Lukatsky, AP

At a news conference, Russian Foreign Minister Sergey Lavrov said: “It’s not an unfounded suspicion, we have serious reasons to believe that such things could be planned.”

Ukraine has rejected Moscow’s claims as an attempt to distract attention from its own plans to detonate a dirty bomb. German Defence Minister Christine Lambrecht dismissed as “outrageous” the claim that Ukraine could use a dirty bomb, saying there were “zero indications” of that.

In a televised address, Ukrainian President Volodymyr Zelenskyy suggested that Moscow itself was setting the stage for deploying a radioactive device on Ukrainian soil.

On the battlefield, his office said at least six civilians were killed and another five were wounded by Russian shelling of several Ukrainian regions over the past 24 hours, including Mykolaiv - where energy facilities were targeted - and the city of Bakhmut in the eastern Donetsk region.

Russian authorities said Ukrainian troops fired rockets at a major hydroelectric power plant in the Kherson region. Russian news agencies cited regional emergency services as saying the Ukrainian military had fired 19 rockets at the Kakhovka plant and scored three hits.

A Ukrainian serviceman checks trenches dug by Russian soldiers in a retaken area in Kherson region. Photo / Leo Correa, AP

Vladimir Rogov, a senior member of the Kherson regional administration, said the plant hadn’t sustained serious damage and continued to operate. Russia and Ukraine have both accused each other of plotting to blow up the plant’s dam to flood the area as Ukrainian forces were pressing an offensive on Kherson, which was captured by Russian troops early in the war.

Ukraine’s relentless artillery strikes on Kherson have cut the main crossings across the Dnieper River, which bisects southern Ukraine, and have left Russian troops on the west bank short of supplies and vulnerable to encirclement. The region is one of four that Russian President Vladimir Putin illegally annexed last month and put under Russian martial law last week.

Budanov, the Ukrainian intelligence chief, played down speculation that Russian forces were preparing an immediate exit from Kherson.

While Russian forces were helping hundreds of officials and residents evacuate, “at the same time, they are bringing new military units in and preparing the streets of the city for defense,” he was quoted as saying.

Meanwhile, Russian authorities removed monuments of 18th-century Russian military chiefs Alexander Suvorov and Fyodor Ushakov from Kherson to save them from Ukrainian shelling.

Russian-installed authorities have told all residents of Kherson to leave “immediately” ahead of an expected advance by Ukrainian troops waging a counteroffensive to recapture the city, which sits on a key route to the Russian-occupied Black Sea peninsula of Crimea.

A poll released from the Kyiv International Institute of Sociology showed 86 per cent of Ukrainian respondents agreed that Ukraine’s armed struggle with Russia should continue. Some 10 per cent believed it was necessary to start negotiations with Russia even if Ukraine has to make concessions.

Residents in Mykolaiv, northwest of Kherson, echoed the determination to fight on - even as their city endures shelling almost every night and residents must line up during the day for food and water.

“Ukraine is doing the right thing. Russians attacked us, and they must be beaten for that,” said Mykolaiv resident Mykola Kovalenko, 76. “Of course, my life changed. I live with constant pressure.”

With an eye on the coming winter, Kyiv and seven other Ukrainian regions have planned rolling blackouts as authorities worked to fix the damage to energy facilities caused by Russian shelling.

Zelenskyy said repair crews are working to restore electricity supplies cut off by large-scale Russian missile strikes, and appealed to local authorities to make sure Ukrainians heed a call to conserve energy.

“Now is definitely not the time for bright storefronts and signs,” he said.

- Andrew Meldrum, AP