Powerful explosions rattled the southern Ukrainian city of Mykolaiv on Thursday and a city close to the country's biggest nuclear power plant sustained a barrage of shelling amid Russian attacks in several regions, Ukraine's presidential office said. At least four civilians were killed and 10 more wounded over the past 24 hours, with nine Ukrainian regions coming under fire, the office said in its daily update. Two districts of Mykolaiv, which has been targeted frequently in recent weeks, were shelled. Russian forces reportedly fired 60 rockets at Nikopol, in the central Dnipropetrovsk region. Some 50 residential buildings were damaged in the city of 107,000 and some projectiles hit power lines, leaving city residents without electricity, according to Ukrainian authorities. Nikopol is located across the Dnieper river from the Zaporizhzhia nuclear power plant, which was taken over by Russian troops early in the war. Experts at the U.S.-based Institute for the Study of War believe that Russia is shelling the area intentionally, “putting Ukraine in a difficult position." Read:US says Russia aims to fabricate evidence in prison deaths “Either Ukraine returns fire, risking international condemnation and a nuclear incident (which Ukrainian forces are unlikely to do), or Ukrainian forces allow Russian forces to continue firing on Ukrainian positions from an effective ‘safe zone,’” the Institute’s latest report said. The head of the U.N. nuclear watchdog agency earlier this week voiced alarm over the situation at the Zaporizhzhia plant. In northern Ukraine, the country's second-largest city, Kharkiv, was being shelled from Russia, the presidential office said. Several industrial facilities were hit in the city, which also has been a frequent target. In the nearby city of Chuhuiv, a rocket hit a five-story residential building. In the eastern Donetsk region, where fighting has been focused in recent weeks, residential buildings were being shelled in all large cities and a school was destroyed in the village of Ocheretyne. The region is struggling without gas supplies and, in part, without power and water supplies; its residents are being evacuated. Russia-backed separatist authorities in the city of Donetsk said that two people were killed and three others wounded in Ukrainian shelling of the central part of the city on Thursday. Russian forces have already seized the neighboring Luhansk region. Its Ukrainian governor, Serhiy Haidai, said on social media that local residents are being mobilized to fight against Kyiv's forces and that “even indispensable mine workers are being taken.” Ukrainian authorities reported another abduction of a mayor who reportedly refused to collaborate with the Russians in the southern Kherson region, which is also almost entirely occupied. The reported kidnapping of Serhiy Lyakhno, the mayor of the village of Hornostaivka, comes as Russia amasses more troops in the area in anticipation of a counteroffensive by Kyiv and ahead of a planned referendum on the region becoming part of Russia.

Cruise missiles fired by Russian strategic bombers struck a southeastern Ukrainian city late Friday, killing at least three people and wounding 15, as air raid sirens went off across the country, officials said. The attack on Dnipro came a day after a Russian missile strike killed at least 23 people and wounded more than 200 in Vinnytsia, a city southwest of Kyiv, the capital. Russia’s military campaign has been focusing on the Donbas in Ukraine’s east, but Russian forces also have been pounding other parts of the country in a relentless push to wrest territory from Ukraine and soften the morale of its leaders, civilians and troops as the war nears the five-month mark. Ukraine’s air force said several Kh-101 cruise missiles fired from Tu-95MS strategic bombers over the Caspian Sea hit a factory about 10 p.m. in Dnipro, a major city on the Dnieper River. Four incoming missiles were intercepted, it said. Videos posted on social media showed fiery explosions and towering plumes of dark smoke. The regional governor, Valentyn Reznichenko, said the missiles hit the factory and nearby streets, killing at least three people and wounding 15. One of the dead was a bus driver who had just finished work and was returning to the depot when a missile struck, said Ivan Vasyuchkov, a member of the city council. The emergency service said two vehicles were burned up and 10 others were damaged. The missile strikes also set the factory on fire and blew out windows in nearby apartment buildings. Airstrikes also were reported in Kremenchuk, another city along the Dnieper River south of Kyiv. Ukrainian President Volodymyr Zelenskyy urged everyone to heed air raid sirens and seek cover. “The occupiers are realizing that we are gradually becoming stronger and the purpose of their terror is very simple — to put press on us, to put pressure on our society, to intimidate people, to cause maximum harm to Ukrainian cities, at least while the Russian terrorists are still capable of doing it,” he said in his nightly video address to the nation. Also read: Russian missiles kill at least 23 in Ukraine, wound over 100 The attack on Vinnytsia by cruise missiles launched from a Russian submarine was the latest to fan international outrage since Russian President Vladimir Putin began the invasion on Feb. 24. The dead included three children: a 4-year-old girl, and two boys, 7 and 8.  “She was reaching for her daughter, and Liza was already dead,” the mother’s aunt, Tetiana Dmytrysyna, told The Associated Press on Friday. “The mother was robbed of the most precious thing she had.” A video of Liza playing earlier in the day and a photo of her lifeless body have gone viral worldwide. Ukraine’s Interior Ministry said Friday that Russian forces had conducted more than 17,000 strikes on civilian targets during the war, killing thousands of fighters and civilians and driving millions from their homes. The invasion has also rippled through the world economy by hiking prices and crimping exports of key Ukrainian and Russian products such as grain, fuel and fertilizer. As the fighting raged, Russia noted progress in talks on a possible deal to allow Ukraine to use the Black Sea to export millions of tons of grain that could help feed a world facing shortages and higher food prices. Alluding to talks in Istanbul this week among Russia, Turkey, Ukraine and the United Nations, Russian Defense Ministry spokesman Lt. Gen. Igor Konashenkov said a final document had been prepared and that other participants had “largely supported” Russian proposals to help ease grain shipments through Ukrainian ports. He said work on the “Black Sea initiative” was to be completed shortly to allow shipments of food “while excluding the use of those logistical chains for the deliveries of weapons and military equipment” to Ukraine. He also said the plan seeks to “prevent any provocations.” About 22 million tons of grain have been stuck in Ukraine because of the war. It was the most extensive Russian comment yet on the grain talks, which mostly involved military officials. U.N. Secretary-General Antonio Guterres said Russia and Ukraine had taken “a critical step” toward ensuring exports of the desperately needed grain. After Thursday’s strike on Vinnytsia, nearly 200 people sought medical attention and 80 remain hospitalized, the emergency service said. Zelenskyy said four people were still missing. Search teams were poring over two sites Friday — an office building with a medical center and a concert hall near an outdoor recreation area where mothers with children often stroll. “Russia deliberately hit civilians and all those responsible for the crime must be brought to account,” said Vinnytsia Gov. Serhiy Borzov, denouncing the “barbaric behavior by Russia that tramples on international humanitarian law.” Kyrylo Tymoshenko, a deputy head of the Ukrainian president’s office, said three missiles were used. “There is no answer to the question why yesterday, and why in Vinnytsia,” Tymoshenko said. “We expect every second and minute that this could happen in any corner of Ukraine.” After initial silence about the missile strikes on Vinnytsia, Russia’s Defense Ministry said Friday that its forces had struck an officers’ club — the Soviet-era use of the concert hall. Konashenkov, the Russian Defense Ministry spokesman, said the Kalibr cruise missiles landed as the “military facility hosted a meeting between Ukrainian air force command and representatives of foreign weapons suppliers.” He said attendees were discussing prospective supplies of warplanes and weapons. “Participants of the meeting were eliminated in the strike,” Konashenkov said. His claim couldn’t be independently verified. Ukrainian authorities have insisted the site had nothing to do with the military. A Ukrainian singer reported that she had been scheduled to perform in the concert hall Sunday and that her sound engineer was killed in the missile strike. The singer, Roxolana, said on social media that another member of her crew was seriously injured. In the Donetsk region, the governor reported that eight civilians were killed and 13 wounded Friday when several cities came under Russian shelling. The Donetsk region and the neighboring Luhansk region — now nearly totally controlled by Russian forces — make up the broader Donbas. “The situation in the Donetsk region is exacerbating every day, and civilians must leave because the Russian army is using scorched-earth tactics,” Donetsk Gov. Pavlo Kyrylenko said. It appeared that the cities of Kramatorsk and Sloviansk were next in line for attacks by Russian forces. Elsewhere, authorities in Mykolayiv said at least 10 explosions occurred in the southern city early Friday, accusing Russia of hitting universities. Mykolayiv Gov. Vitaliy Kim posted a video of smoke rising over the strikes. The Russian news agency Tass, citing Russian-backed separatists, reported Friday that two civilians were killed and six injured after they said Ukrainian forces shelled a bus terminal in the city of Donetsk a day earlier. Also, a British aid worker detained by the Donetsk separatists has died in captivity, a separatist official and a U.K. charity involved with his case said Friday. Punitive political actions over the war continued, with Russian state news media reporting Friday that the Kremlin had barred 384 members of Japan’s parliament from entering Russia, citing retaliation for Japan’s sanctions against Russian parliament members.