Ukrainian military officers and civilians shop at a street market in Bakhmut
Ukrainian military officers and civilians shop at a street market, as Russia's attack in Ukraine continues, in Bakhmut, Donetsk region, Ukraine August 21, 2022.

Ukraine's capital Kyiv banned public celebrations this week to commemorate independence from Russian-dominated Soviet rule and its second city Kharkiv declared a curfew due to a heightened threat of Russian attack, local authorities said.

Near frontlines in the south of the country, Ukraine said Russia fired rockets into several southern Ukrainian 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 Russian-occupied 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 what it calls a "special military operation" on Feb. 24 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.

Son hugs his mom, during the evacuation from war-affected areas in eastern Ukraine, in Bakhmut
Son hugs his mom, during the evacuation from war-affected areas in eastern Ukraine, as Russia's attack in Ukraine continues, in Bakhmut, Donetsk region, Ukraine August 20, 2022.

Ukrainian President Volodymyr Zelenskiy warned at the weekend of the risk of more severe attacks ahead of Ukraine's 31st anniversary on Wednesday of independence from Russian-dominated Soviet rule.

Local authorities in Kyiv have banned large public events, rallies and other gatherings related to the anniversary in the capital from Monday until Thursday due to the possibility of rocket attacks, according to a document published by the Kyiv military administration and signed by its head Mykola Zhyrnov.

Ihor Terekhov, mayor of Kharkiv in the northeast which has come under frequent and deadly long-range Russian bombardment, extended a regular overnight curfew to run from 4 p.m. to 7 a.m. effective from Tuesday to Thursday.

In the port city of Mykolaiv near Russian-occupied territory to the south, regional governor Vitaly Kim said authorities were preparing a precautionary order for residents to work from home on Tuesday and Wednesday and urged people not to gather in large groups.

Zaporizhzhia Nuclear Power Plant near Enerhodar
A serviceman with a Russian flag on his uniform stands guard near the Zaporizhzhia Nuclear Power Plant in the course of Ukraine-Russia conflict outside the Russian-controlled city of Enerhodar in the Zaporizhzhia region, Ukraine August 4, 2022.

Zelenskiy, in his nightly video address on Saturday, said Moscow could try "something particularly ugly" in the run-up to Wednesday, which also marks half a year since Russia invaded.

He said he had discussed "all the threats" with his French counterpart and word had also been sent to other leaders including Turkish President Tayyip Erdogan and U.N. Secretary-General Antonio Guterres.

"All of Ukraine's partners have been informed about what the terrorist state can prepare for this week," Zelenskiy said in his nightly video address, referring to Russia.

The Financial Times, in an article published on Sunday, quoted Gennady Gatilov, Moscow's ambassador to the United Nations in Geneva, as saying Erdogan had tried to facilitate dialogue.

Russia's attack on Ukraine continues, in Nikopol
Zaporizhzhia Nuclear Power Plant is seen from an embankment of the Dnipro river in the town of Nikopol, as Russia's attack on Ukraine continues, in Dnipropetrovsk region, Ukraine July 20, 2022.

But he dismissed speculation about talks between Zelenskiy and Russian President Vladimir Putin, saying there was no "practical platform for having this meeting", the report said.

NUCLEAR RISK

Ukraine and Russia have traded blame for repeated incidents of shelling in and around the premises of the Zaporizhzhia nuclear reactor complex, on the Russian-occupied south bank of the Dnipro River, in recent weeks.

Kyiv has accused Moscow of basing troops and storing military equipment on the grounds of the power station and using it as a shield from which to bombard Ukrainian government-controlled territory to the west and north. Russia denies this and accuses Ukraine of targeting the plant with shells and drones.

A woman walks near a damaged building in Mariupol
A woman walks near a building damaged in the course of Ukraine-Russia conflict in the southern port city of Mariupol, Ukraine August 21, 2022.

Overnight on Monday, Russian forces fired rockets into Nikopol, just across the Dnipro from the plant on its south bank, as well as the Krivyi Rih and Synelnykovskyi districts further out to the northwest and northeast respectively, regional Governor Valentyn Reznichenko wrote on Telegram.

Ukraine also reported a Russian missile strike on Voznesensk, to the southwest and not far from the country's second-largest atomic power station.

On Sunday, U.S. President Joe Biden, British Prime Minister Boris Johnson, German Chancellor Olaf Scholz and French President Emmanuel Macron held a phone call stressing the importance of ensuring the safety and security of Ukraine's nuclear installations.

They also welcomed recent discussions on enabling a mission by the U.N. nuclear watchdog agency to Zaporizhzhia, while reaffirming their "steadfast commitment" to support Ukraine in the face of Russia's invasion.

The conflict, Europe's biggest since World War Two, has destroyed towns and cities, killed thousands of people, forced millions to flee abroad and deepened a geopolitical chasm between Russia and the West.

Since Ukraine repelled a Russian attempt to capture Kyiv early in the war, the fighting has been concentrated in the east and south where frontlines have been largely static for weeks.

In its morning update on Monday, Ukraine's General Staff said Russian forces had made incremental advances into the Blahodnatne area in the direction of Mykolaiv.

Russia was also trying to regain momentum towards Pisky, Bakhmut and Kramatorsk, key towns in Donetsk province which, along with neighbouring Luhansk, captured by Moscow's forces earlier in the summer, comprise the eastern Donbas region.

Russian artillery and multiple rocket launcher systems hammered the areas of Soledar, Zaytseve and Bilohorivka near Bakhmut, the Ukrainian military command's update said.

At least two civilians were killed, the regional administration said. Russia denies targeting civilians.

Reuters was not able to independently verify the battlefield reports.

A worker stands on an excavator in front of a destroyed apartment building in Mariupol
A worker stands on an excavator in front of a destroyed apartment building, that is being demolished, in the course of Ukraine-Russia conflict in the southern port city of Mariupol, Ukraine August 21, 2022.