Russia-Ukraine updates: Russian missiles hit close to nuclear reactors: IAEA director

A Ukrainian firefighter who responded to the Russian missile attacks in Kharkiv overnight told ABC News that the scale of the blasts was "one of the biggest" he's ever seen.

One of the rockets struck a large apartment block on Wednesday night, killing at least nine people and injuring another 16, according to Ukrainian authorities.

"It went through all four floors and hit the ground and almost blew up everything," the firefighter, Roman Kachanov, told ABC News during an interview on Thursday. "All the buildings around were without windows."

"There was a dormitory, and the building was almost completely ruined," he added. "There was a playground that was smashed like a big titan blew it up."

Kachanov is among the rescue workers searching for survivors amid the smoldering rubble.

"I’ve seen three bodies on the floor covered by objects," he said. "We tried to extract them and while we tried, the other wall started to fall and we had to run away as fast as we can."

Kachanov said another missile hit the city before dawn Thursday, not far from where he and his team were working. He said the blast "was very loud" and "sounded close."

"Everyone had to lay down," he recalled. "The team had to split -- fire truck had to leave to go to that other fire."

-ABC News' Britt Clennett, Dragana Java, Natalya Kushnir and Sohel Uddin

At least seven people are dead and another 13 injured by strikes on a large apartment block in Kharkiv, officials said.

Based on recovered shrapnel, authorities determined an Iskander-M missile system was used in the strike, said Ivan Sokol, Ukraine's director of the regional Department of Civil Defense.

>Search and rescue efforts are ongoing at the three-story residential building, the State Emergency Service of Ukraine said.

-ABC News' Tatiana Rymarenko

More shelling was underway Monday in city of Enerhodar, which is under Russian control and where the Zaporizhzhya Nuclear Power Plant is located.

Enerhodar Mayor Dmytro Orlov urged residents to stay inside. He said Russian forces seized another government facility in Enerhodar, a lab where 30 of the employees are refusing to cooperate with the Russian-appointed administration.

Meanwhile, Russia's semi-official Interfax reported that Ukrainian forces opened fire in Enerhodar.

Ukraine's state nuclear regulator Energoatom said the plant remained occupied and controlled by Russian forces on Monday. The Ukrainian staff continues to work and make every effort to ensure nuclear and radiation safety, but Energoatom warned that periodic shelling by Russian troops with multiple rocket launchers since last week caused a serious risk to the safe operation of the plant.

In his daily address, Ukrainian President Volodymyr Zelenskyy said Russian troops must immediately withdraw from the plant. If a catastrophe occurs, Zelenskyy warned it could affect neighboring countries.

-ABC News' Christine Theodorou, Fidel Pavlenko, Natalia Shumskaia and Yulia Drozd

Brittney Griner’s defense team filed an appeal for the verdict by Khimky City Court, according to Maria Blagovolina, a partner at Rybalkin Gortsunyan Dyakin and Partners law firm.

The WNBA star was found guilty on drug charges in a Moscow-area court this month.

-ABC News' Tanya Stukalova