(Bloomberg) -- Ukraine said at least 23 civilians were killed and 28 wounded near the southeastern city of Zaporizhzhia in a Russian missile strike early Friday.

The people were struck while standing in a line that was preparing to leave the city in a humanitarian convoy bound for nearby occupied areas. They planned to take their relatives to safety or to bring aid, Zaporizhzhia’s regional administration said on its Telegram channel.

Andriy Yermak, President Volodymyr Zelenskiy’s chief of staff, deplored the attack, saying his country needed more military aid to respond accordingly.

“Russia is a terrorist state,” he said on Telegram. “We need more weapons to resolve Russia’s issue.”

Russia denied the attack and blamed Ukraine for it.

The deaths come as Russian President Vladimir Putin prepares on Friday to officially annex parts of Ukraine’s Donetsk, Luhansk, Zaporizhzhia and Kherson regions after referendums -- denounced by the UN as illegal -- were held in these areas. 

The Kremlin wants to annex these territories as soon as possible amid Ukraine’s ongoing counteroffensive, which may foil Putin’s plan to keep under control the areas in Ukraine’s east and south that Russia has already seized. 

The Russian military has intensified shelling of Ukrainian cities and towns near the front line as the war, now in its eighth month, grinds on. Putin earlier this month threatened to step up attacks on Ukraine’s civilian infrastructure.  

(Updates with chief of staff remarks from third paragraph)

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