ZAPORIZHZHIA, Ukraine — At least 23 people have been killed and dozens more injured in a Russian rocket strike on a humanitarian convoy in south Ukraine, local officials say.

A huge crater next to a row of vehicles in the city of Zaporizhzhia testifies to the violence of the attack. Windows and windscreens were smashed in.

The BBC saw half a dozen bodies lying at the scene, apparently civilians. Baggage and coats strewed the tarmac.

One survivor told the BBC her boss had been killed in the attack.

"She had two kids. I left the cafe to use the restroom when it happened. I ran back and tried to find her. The cafe was demolished, there were many bodies around. It was all so very horrifying," Viktoriia Yosypenko said.

Reacting to the attack in the early hours of Friday on the outskirts of the regional capital of the Zaporizhzhia region, Ukrainian President Volodymyr Zelensky said Russia was a "state-terrorist".

He said Russia launched 16 rockets on the city, and vowed to punish perpetrators for "every lost Ukrainian life".

Meanwhile, a Russian-installed local official blamed Ukraine for the attack.

The convoy was hit as people were preparing to travel to the Russian-occupied part of the region to pick up their relatives and also deliver humanitarian aid.

Near the missile's impact crater, the BBC spoke to Kateryna Holoborod, sat on her suitcase in a state of shock.

'We arrived in a line, to join a column going towards Kherson," she said.

"We got out to see what number we had in the queue. Then the first rocket hit, behind the wagons.

"We dropped to the ground. Then the second one hit in the centre of the queue. There was glass everywhere, people screaming and running. I don't remember much.

"It was very scary. I then got up to see what happened, help the injured. I tried to help an injured young man when the third explosion happened."

The attack comes as Russian President Vladimir Putin is preparing for a signing ceremony in Moscow to annex Zaporizhzhia along with Ukraine's Donetsk, Luhansk and Kherson regions.

The move follows self-styled referendums in the eastern and southern regions, which have been condemned by Ukraine and the West as a sham.

Russia invaded Ukraine on 24 February, and Moscow currently controls the majority of the Zaporizhzhia region, including Europe's biggest nuclear power plant there - but not the regional capital.

Moscow-installed regional official Vladimir Rogov blamed "Ukrainian militants" for the Zaporizhzhia attack, Russian state-run media reported.

In a separate development, one person was killed and five injured in overnight Russian strikes by Iskander missiles on the central city of Dnipro, about 70km (43 miles) north of Zaporizhzhia, local officials said.

They said a transport company was targeted, and as many as 52 buses were burnt and another 98 damaged.

Several high-rise buildings, offices and a shop were also hit. — BBC