A member of the Reuters news agency was missing and two others were wounded in a strike on a hotel in the east Ukrainian city of Kramatorsk, the agency said Sunday, with Russian attacks killing 15 civilians across the country in the last 24 hours.
In another deadly day in the two-and-a-half year war, six civilians were also killed in Ukrainian strikes on Russian border regions, Russian officials said.
The attacks came as Kyiv mounts an incursion into Russia's Kursk region, which has rattled Moscow but not slowed its advance in eastern Ukraine.
Ukrainian officials said attacks on Saturday said Sunday killed 15 civilians in the war-battered Donetsk, northeastern Sumy and the southern Kherson regions.
In the east Ukrainian city of Kramatorsk, a search and rescue operation was underway after a strike late on Saturday on the Hotel Sapphire, where Reuters said six of its crew covering the war were staying.
Kramatorsk -- the last major city under Ukrainian control in the Donetsk region -- is often used as a base for aid workers and foreign journalists.
"One of our colleagues is unaccounted for, while another two have been taken to hospital for treatment," Reuters said, adding that it was "urgently seeking more information".
The agency said "three other colleagues have been accounted for" and said it was "working with the authorities in Kramatorsk, and supporting our colleagues and their families."
The head of the Donetsk region, Vadym Filashkin, said earlier two journalists were wounded while one was missing, saying the strike happened "in the middle of the night."
He said a rescue operation was ongoing and "the rubble was being cleared".
'Scary to go to bed'
Ukrainian prosecutors said the hotel was hit by a Russian Iskander missile at 10.35 pm on Saturday, with the strike also damaging the building next door.
AFP saw authorities giving out plywood to locals for them to board their windows.
Kramatorsk lies around 20 kilometres (13 miles) from the frontline, with fears over the city rising as Russian forces continue their push into eastern Ukraine.
Many local residents were going to bed at the time of the strike.
"I was watching a film on my phone and then... there was such a noise and the glass started smashing," 66-year-old Natalia told AFP, crying.
She said she had already been evacuated once after a similar experience but came back, and now will "think about" leaving again.
"It's scary to go to bed," she said, her voice breaking.
Another resident, 84-year-old Vasily who lives close to the hotel, was fixing plywood onto his window frames after the glass smashed during the strike.
"We worry all the time... and now our turn has come," he said, adding: "It's about how lucky you get."
15 dead across Ukraine
Officials said Russian strikes that hit outside the city of Kherson killed three people and wounded six, including a one-year-old boy who was left with shrapnel injuries.
Russian attacks on frontline towns in the Donetsk region killed eight people in the last 24 hours, Donetsk leader Filashkin said.
Officials said large-scale attacks on the Sumy region -- from where Kyiv had launched its surprise incursion on August 6 -- also killed four people on Saturday.
Ukrainian police said Russia had shelled some 50 settlements in the Sumy region.
Kyiv said Russia also attacked the Kharkiv region at night, wounding eight people in the city of Kharkiv.
In Russia, officials said attacks on the Belgorod border region killed six civilians.
Belgorod governor Vyacheslav Gladkov said five people were killed in a strike on the village of Rakitnoye, in an attack that also wounded a dozen people.
He said 13 others were wounded, with six in a "serious condition", including a 16-year-old in intensive care.
Gladkov later said a man was killed by a Ukrainian drone attack in the village of Solovyevka further south.
Ukraine has pushed into parts of the Kursk region after an incursion that has seen more than 130,000 people displaced.