(CN) — Heavy fighting and the shelling of cities were reported Friday across the war zone in Ukraine and military and political battles raged over control of a nuclear power plant in southern Ukraine, raising the specter of a nuclear disaster.
Since Wednesday, Kharkiv, the country's second-largest city near the northeastern border with Russia, has come under heavy shelling. By Friday morning, there were more reports of explosions during the night.
Russia is both seeking to seize the important city, which in the past has had deep pockets of pro-Russian support, and likely eager to keep Ukrainian forces tied up in the city's defense. Kharkiv has come under regular fire from the outset of the invasion.
The death toll from this week's strikes on buildings in Kharkiv's Saltivskyi and Slobidskyi districts rose to 21 after rescuers found more bodies under rubble, according to Ukrinform, a Ukrainian news agency. More than 40 people were wounded.
Russia's Ministry of Defense claimed the strikes killed more than 90 soldiers in Kharkiv, but Ukraine said the attacks killed civilians. Ukrainian officials say more than 1,020 civilians have been killed in Kharkiv. Earlier this week, Human Rights Watch accused Russia of indiscriminately attacking civilian infrastructure and using banned cluster bombs. Amnesty International, meanwhile, issued a report accusing Ukrainian forces of using civilian buildings to hide in.
On Friday, Russia also hit the small cities of Kryvyi Rih, Synelnykove, and Nikopol in Dnipropetrovsk, a region in south-central Ukraine. At least one man was killed in Kryvyi Rih, according to Ukrainian officials. Ukraine reported other strikes on Mykolaiv on the Black Sea and on Chernihiv and Sumy, northern regions close to the Russian border and east of Kyiv.
Dnipropetrovsk and neighboring southern regions are turning into a new major front line as fighting rages between Ukrainian and Russian forces over the Zaporizhzhia Nuclear Power Station. The battles in this region are escalating as Ukraine seeks to mount a counteroffensive and regain control of parts of southern Ukraine it has lost.
The nuclear plant is now the focus of international attention because of the potential of a nuclear disaster there. Both sides accuse the other of shelling the facility and seeking to provoke a catastrophe.
Intense negotiations are taking place between various actors – including the United Nations, Ukraine, the United States, Russia, Turkey and France – to allow international inspectors into the Zaporizhzhia facility.
Ukraine accuses Russia of seeking to disconnect the power plant from Ukraine's power grid and then stop supplying energy to parts of Ukraine not under its control. Russia says it may be forced to close the plant due to Ukrainian shelling. The situation at Zaporizhzhia is chaotic and made worse by conflicting reports.
The plant is being run by workers with Ukraine's atomic energy agency, Energoatom, but Russian nuclear experts and military are in control of its operations. There have been reports of Energoatom workers being kidnapped and of the facility being operated dangerously.
The plant has been under Moscow's control since March 4. It was seized early in the invasion when Russian forces, amassed in Crimea, quickly swept across large portions of southern Ukraine and seized the cities of Kherson, Melitopol, Berdiansk and, eventually after horrific street fighting, Mariupol.
That opening phase of the invasion gave Russia control over the Sea of Azov and allowed it to establish a land corridor between Crimea, which Moscow annexed in 2014, and the rest of Russia.
While fighting is escalating along the southern front, the worst combat continues to take place in Donbas, an eastern region of Ukraine that's been the theater of fighting since an armed insurgency rose up in 2014 against the installation of a pro-Western government following the so-called “Maidan Revolution” that toppled the government of Ukraine's pro-Russian president, Viktor Yanukovych.