POLTAVA, Ukraine — More than 50 people were killed and hundreds injured in a Russian missile attack on the central Ukrainian city of Poltava on Tuesday, which struck a military educational institute and a nearby hospital, making it one of the deadliest single bombardments of the war.

       By Tuesday evening, scenes of horror now familiar in cities across Ukraine had emerged: Volunteers with search-and-rescue dogs arrived to help locate victims under the rubble. A small excavator pushed aside debris from a hollowed-out building. Air raid sirens blared yet again around 6:30 p.m., forcing rescuers to pause for half an hour and seek shelter before resuming their work.

       Two ballistic missiles struck the city, President Volodymyr Zelensky said, adding that many people were trapped under the rubble.

       The attack coincided with a renewed push by Ukrainian leaders to urge allies to lift restrictions on allowing Kyiv to use long-range weapons on military targets inside Russia. Ukraine has long said that the rules imposed by allies, including the United States, make Kyiv unable to prevent missile attacks across the country by destroying Russian military infrastructure.

       “We continue to urge everyone in the world who has the power to stop this terror: Ukraine needs air defense systems and missiles now, not sitting in storage,” Zelensky said Tuesday. “Long-range strikes that can protect us from Russian terror are needed now, not later. Every day of delay, unfortunately, means more lost lives.”

       Casualties from Tuesday’s strikes rose steadily as bodies were recovered from the wreckage. The Foreign Ministry reported in the evening that the death toll had risen to 51, with more than 200 injured.

       The Defense Ministry said that the time between the alarm and the impact was so short that many people were caught trying to reach bomb shelters.

       In interviews, people who study or work at the institute — or their friends and relatives, who answered questions while waiting for updates at nearby hospitals — described hearing the air raid sirens while indoors and heading downstairs to the bomb shelter.

       Some didn’t make it in time.

       One man at a nearby hospital, who declined to give his name, said he was dressed normally — not in a military uniform — for a day of coursework. He evacuated the building to go to the shelter after hearing news of the incoming missiles and later sought medical treatment for a wound to his left elbow. His bandage was soaked with blood.

       Nearby, a man spoke on the phone to a relative, describing a large number of badly wounded people with missing limbs. The grave injuries necessitated the use of tourniquets, Post reporters heard him say.

       Outside, police investigators interviewed witnesses. One described to the officers how he had descended the stairs as the first missile hit. He told them he climbed out from under the rubble and left the building using the remnants of the stairs.

       A 72-year-old man who lives in a nearby apartment building overlooking the educational campus said a former colleague had lost his arm in the blast.

       “There was very little time between the start of the air raid sirens and the explosion,” said Volodymyr, who spoke on the condition that only his first name be used because of security concerns. “After 15 seconds, there was a second incoming missile. … Right now, everyone is in shock.”

       The strike hit the Military Institute of Telecommunications and Information Technology. It was not immediately clear who was present at the time of the strike, but classes started in Ukraine on Monday, and it is likely that students of the institute were on campus at the time of the attack.

       The institute educates young cadets, as well as experienced military personnel pursuing bachelor’s or master’s degrees. Its website says that graduates receive a state diploma and the rank of lieutenant, and then proceed to serve in Ukraine’s military.

       “Usually there are just students studying here every morning,” said Serhiy Homenko, leaning out of a neighbor’s second-floor window, which he was helping to repair. “They are young — 20, 21 — and wear normal clothes.”

       In many parts of the country, schooling has not taken place in person since the 2022 invasion over fears that students would be hit in airstrikes or missile barrages.

       At a hospital, Olena, whose son-in-law worked at the school, said that he had gone down to the bomb shelter after the air raid sirens wailed. His colleague, she said, “stood outside to smoke, and when the explosion happened, he went flying,” along with his “cigarette and the door and everything around them.”

       The woman, who stood in a hospital corridor, declined to give her last name but described “everyone running around, covered in blood. I have never seen anything like this in my life. Those poor boys, screaming out. It’s horrible.”

       Regional Poltava leader Philip Pronin called it “a terrible day” for the city. The region will observe three days of mourning beginning Wednesday, officials said.

       Pronin said that the actions of rescuers and medical professional had “saved many lives” and that residents were already donating blood to help the injured. He urged others to sign up to give more.

       Ukrainian public broadcaster Suspilne reported a flood of wounded being transported to medical facilities in the city, especially the Sklifosovsky Regional Hospital. “Almost all operating tables, teams and anesthesiology teams were engaged,” said hospital official Valentyn Bilyi. “There are burn injuries, explosive injuries, fractures and combined injuries, including shrapnel wounds.”

       Just after the evening’s air raid alert ended, Oleksandra Karpova, 28, unloaded her black-and-gray rescue dog, Mria, or “Dream,” in hopes of recovering victims from the rubble. Mria was trained to locate the living. Over the weekend, the 6-year-old dog had helped recover a survivor from the shelling of the Palace of Sports in Kharkiv.

       Here, they hoped to do the same.

       “We still don’t know how long we will be here today,” Karpova said.

       If Mria wasn’t successful, search dogs with a different specialty — locating the dead — would be called the following day.

       After the Poltava attack, Latvian President Edgars Rinkevics also called for the lifting of restrictions on Ukraine’s ability to strike targets inside Russia.

       “One more time: restrictions imposed on Ukraine to use all weapons against Russia must be lifted. This is not about escalation, this is about the survival of innocent people,” he said on X.

       Meanwhile, a large government shake-up occurred Tuesday, with several high-level officials submitting their resignations, including Justice Minister Denys Maliuska, Minister of Strategic Industries Oleksandr Kamyshin and Environment Minister Ruslan Strilets. Kamyshin is Ukraine’s arms chief and has overseen domestic production of weapons. He wrote on Telegram that he will still serve a role in the defense sector. Deputy Prime Minister Olha Stefanishyna, who has overseen Ukraine’s push to join the European Union, also submitted her resignation.

       A new roster of top officials is expected to be announced in the coming days, probably ahead of an upcoming visit by Zelensky to the United States, where he is expected to present a “victory plan” for Ukraine.

       Before the Poltava attack, Russia launched a number of strikes on Ukraine overnight, including one on the southeastern Zaporizhzhia region that killed two people, including an 8-year-old. A missile attack on the city of Dnipro killed another person.

       Over the past week, there has been a renewed surge of missile and drone strikes from Russia against targets across the country, including in the capital, Kyiv, and against Ukraine’s electricity infrastructure.

       Ukraine has also attacked oil refineries in Russia with drone strikes.

       Amid the resurgence in attacks, there has been renewed worry over the fate of the region’s nuclear power plants, including the Russian-occupied one in Zaporizhzhia, the largest in Europe.

       Rafael Grossi, director general of the International Atomic Energy Agency, will visit the plant this week in the wake of a similar trip to the nuclear power plant in Russia’s Kursk region, where Ukrainian troops have seized some 500 square miles of territory.

       Speaking to reporters in Kyiv on Tuesday, Grossi — who had just emerged from a meeting with Zelensky — said he had not made any specific requests of Ukraine’s leader in regard to avoiding strikes on the Zaporizhzhia plant.

       “I don’t think he disagrees at all on the fact that nuclear power plants should never be attacked,” Grossi said.

       The nuclear watchdog head said Zelensky had asked that the IAEA examine Ukrainian substations connected to Ukraine’s nuclear power plants that have come under Russian attack. Grossi said the IAEA agreed Tuesday to begin such a process at some substations by next week.

       O’Grady reported from Kyiv and Hassan from London. Serhii Korolchuk in Kyiv and Anastacia Galouchka in Kharkiv, Ukraine, contributed to this report.