The Lysychansk Gymnasium, an acclaimed secondary school in Ukraine's Luhansk region, burned to the ground after coming under fire in targeted shelling, said Serhiy Haidai, the head of Luhansk's Regional Military Administration. The school was more than a century old.

-ABC News' Max Uzol and Irene Hnatiuk

Ukrainian forces have carried out an offensive in the country's Kharkiv region, taking back control of several settlements, Ukraine's Ministry of Defense said Monday. This includes the settlements of Verkhnya Rohanka, Ruska Lozova, Slobidske and Prilesne.

-ABC News' Irene Hnatiuk

U.S. Embassy staff returned to Ukraine for the day on Monday, marking the first trip back in the country since February.

"We expect to continue to do day trips for the next week or two and we very much hope that the conditions will permit us to go back to Kyiv by the end of the month," Kristina Kvien, the U.S. chargé d'affaires to Ukraine, said in a statement.

Kvien said, "The message to Russia is: you failed -- Ukraine is still standing, the government is still functioning and we are going back to Lviv first and then Kyiv to help the government."

Kvien continued, "We are listening to the security professionals and when they tell us we can go back we go back. And while we are eager to do so we also want to make sure we are listening to the experts. So, the fact that we are here in Ukraine means that the security officials just said that it is ok and safe to meet here in Lviv and hopefully we will get the clearance to go back to Kyiv."

-ABC News' Clark Bentson

Dozens of civilians trapped for weeks inside a steel plant in the devastated Ukrainian city of Mariupol were expected to reach Zaporizhzhia on Monday, according to Ukrainian President Volodymyr Zelenskyy.

In a statement posted to Twitter on Sunday, Zelenskyy said a first group of about 100 people were already en route to the Ukrainian government-controlled city, about 140 miles northwest of Mariupol.

"Tomorrow we'll meet them in Zaporizhzhia," Zelenskyy tweeted. "Grateful to our team!"

Many more civilians remain trapped at the sprawling Azovstal Iron and Steel Works plant in Mariupol -- the last holdout of Ukrainian resistance to Russia's bombardment of the strategic southeastern port city -- which Russian forces resumed shelling overnight.

"Today, for the first time in all the days of the war, this vitally needed green corridor has started working," Zelenskyy said Sunday in his nightly address.

At least one person -- a journalist -- was killed in a rocket attack on a residential building in Kyiv on Thursday evening, ABC News has learned.

Kyiv Mayor Vitali Kilitschko said Friday that rescuers had found the body of a victim amid the rubble.

Radio Liberty, a service of the U.S.-funded Radio Free Europe/Radio Liberty, reported that one of its employees, Vira Gyrych, was killed when a Russian missile hit her apartment in the Ukrainian capital on Thursday. Her body was found beneath the wreckage Friday morning, according to the report.

Gyrych had worked as a journalist and producer for Radio Liberty's Kyiv bureau since 2018. Prior to that, she worked for leading Ukrainian television channels, according to Radio Liberty.

"The editorial staff of Radio Liberty expresses its condolences to the family of Vira Gyrych and will remember her as a bright and kind person, a true professional," Radio Liberty said in its report.

Israeli Ambassador to Ukraine Michael Brodsky also confirmed Gyrych's death in a Twitter post, saying she was a former employee of the Israeli embassy in Kyiv.

Thursday's rocket attack came as United Nations Secretary-General Antonio Guterres visited Kyiv. Five Russian missiles flew into the city, according to Ukrainian President Volodymyr Zelenskyy. At least 10 people were injured, including four who were hospitalized, according to the Kyiv City Council.