Ukraine bans Independence Day festivities citing Russian threat
* Moscow could try 'something particularly ugly', Zelenskiy says
* Russia blames Ukraine for ultra-nationalist killing in Moscow
* U.N. says 5,587 civilians killed in conflict so far
* Ukraine says nearly 9,000 soldiers killed in first estimate
By Pavel Polityuk
KYIV, Aug 22 (Reuters) - Ukraine's capital Kyiv banned public celebrations this week to commemorate independence from Soviet rule, citing a heightened threat of Russian attack in a war that the United Nations said on Monday has killed more than 5,500 civilians.
Near frontlines in the south of the country, Ukraine said Russia fired rockets into several towns north and west of Europe's largest nuclear power plant, captured by Russian forces shortly after they invaded Ukraine in February.
Artillery and rocket fire in the region of the Zaporizhzhia nuclear reactor complex, on the south bank of the Dnipro River, has stirred fears of a nuclear disaster and led to calls for the surrounding area to be demilitarised.
Russia launched on Feb. 24 what it calls a "special military operation" to demilitarise its smaller neighbour and protect Russian-speaking communities. Ukraine and its Western backers accuse Moscow of waging an imperial-style war of conquest.
Ukrainian President Volodymyr Zelenskiy said at the weekend that Moscow could try "something particularly ugly" in the run-up to Wednesday's 31st independence anniversary, which also marks half a year since Russia invaded.
Kyiv local authorities have banned public events related to the anniversary from Monday until Thursday due to the possibility of rocket attacks, a document showed.
The capital is far from front lines and has only rarely been hit by Russian missiles since Ukrainian defenders repelled a Russian ground offensive to seize the capital in March.
In Kharkiv, a northeastern city that has come under frequent and deadly longer-range artillery and rocket fire, Mayor Ihor Terekhov announced an extension to an overnight curfew to run from 4 p.m. to 7 a.m. effective from Tuesday to Thursday.
In the port of Mykolaiv near Russian-held territory to the south, regional governor Vitaliy Kim said authorities planned a precautionary order for residents to work from home on Tuesday and Wednesday and urged people not to gather in large groups.
Fears of intensified attacks were likely to rise after Russia's Federal Security Service accused Ukrainian secret services on Monday of killing Darya Dugina, daughter of a Russian ultra-nationalist ideologue, in a suspected car bombing on Saturday, Russian news agencies reported. Ukraine has denied being involved.
The Office of the U.N. High Commissioner for Human Rights, citing its monitoring mission in Ukraine, said on Monday 5,587 civilians had been killed and 7,890 wounded between Feb. 24 and Aug. 21, mainly from artillery, rocket and missile attacks.
Separately, General Valeriy Zaluzhnyi - Kyiv's army chief - provided what appeared to be the first public Ukrainian military death toll, saying nearly 9,000 soldiers had died in action.
Russia has not said how many of its soldiers have been killed. Ukraine's General Staff have estimated the Russian military death toll at 45,400.
Reuters has been unable to verify the military losses by either side.
Moscow requested a U.N. Security Council meeting be held on Tuesday to discuss the Zaporizhzhia plant, Russian state-owned news agency RIA reported, citing Deputy Ambassador to the U.N. Dmitry Polyanskiy.
Kyiv has accused Moscow of basing troops and storing military hardware on the grounds of the power station and using it as a shield from which to bombard Kyiv government-controlled territory to the west and north. Russia denies this and accuses Ukraine of targeting Zaporizhzhia with shells and drones.
Overnight, Russian forces fired rockets into nearby Nikopol, Krivyi Rih and Synelnykovskyi, regional Governor Valentyn Reznichenko wrote on Telegram.
In a phone call on Sunday, the leaders of the United States, Britain, France and Germany stressed during a joint call the importance of ensuring the safety of nuclear sites in Ukraine, British Prime Minister Boris Johnson's office said.
Europe's biggest conflict since World War Two has destroyed towns and cities, killed thousands of people, forced millions to flee abroad and deepened a volatile geopolitical stand-off between Russia and the West.
Since Russian forces retreated in disarray from Kyiv early in the war, they have concentrated on seizing the rest of the eastern Donbas region partially held by separatist proxies since 2014, and holding on to captured swathes of the south.
In the latest sign of a planned Ukrainian counter-offensive to retake the Kherson region in the south, smoke was rising from the sole bridge across the Dnipro in Kherson city, a Kyiv interior ministry adviser said.
A source in occupied Kherson's emergency services told Russia's Interfax news agency that the Antonivskyi bridge was hit by high-precision HIMARS rockets supplied to Ukraine by the United States, and that 15 people had been injured.
The bridge, a key crossing for Russian military transport in the region, has been repeatedly targeted by Ukrainian forces.
The Crimean peninsula, annexed by Russia in 2014, has been rocked by a series of explosions in the past two weeks. Moscow blamed a blast at a munitions depot in the north of the region on saboteurs.
The Russian-appointed governor of the Crimean city of Sevastopol said on Monday that an anti-air defence system had been triggered nearby after Russian media reported that explosions were heard in the city.
Mikhail Razvozhayev said on Telegram an object had been shot down.
In eastern Donetsk province, Russian artillery and multiple rocket launchers battered Soledar, Zaytseve and Bilohorivka near the city of Bakhmut, and at least two civilians were killed, Ukrainian authorities said. Russia denies targeting civilians.
Reuters was not able to independently verify the battlefield reports of either side.
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Reporting by Ron Popeski and Natalia Zinets; Writing by Himani Sarkar, Mark Heinrich and Nick Macfie; Editing by Stephen Coates, Hugh Lawson and Catherine Evans