KYIV, Ukraine — A Russian strike on the Ukrainian city of Zaporizhzhia killed at least 23 people and wounded dozens, an official said Friday, just hours before Moscow planned to annex more of Ukraine in an escalation of the seven-month war.

Zaporizhzhia Regional Governor Oleksandr Starukh made the announcement in an online statement Friday. He said there were at least 28 wounded when Russian forces targeted a humanitarian convoy heading to Russian-occupied territory.

He posted images of burned out vehicles and bodies lying in the road. Russia did not immediately acknowledge the strike.

The attack comes as Moscow prepares to annex four regions into Russia after an internationally criticized, gunpoint referendum vote as part of its invasion of Ukraine. Those regions include areas near Zaporizhzhia, but not the city itself, which remains in Ukrainian hands.

Starukh said those in the convoy planned to travel into Russian-occupied territory to pick up their relatives and then take them to safety. He said rescuers were at the site of the attack.

The annexation — and planned celebratory concerts and rallies in Moscow and the occupied territories — would come just days after voters supposedly approved Moscow-managed “referendums” that Ukrainian and Western officials have denounced as illegal, forced and rigged.

Kremlin spokesman Dmitry Peskov told reporters Thursday that four regions of Ukraine — Luhansk, Donetsk, Kherson and Zaporizhzhia — would be folded into Russia during a Kremlin ceremony attended by President Vladimir Putin, who is expected to give a major speech. Peskov said the regions’ pro-Moscow administrators would sign treaties to join Russia in the Kremlin’s ornate St. George’s Hall.

In an apparent response, Ukrainian President Volodymyr Zelenskyy called an emergency meeting Friday of his National Security and Defense Council.

Zelenskyy also sought to capitalize on anti-war sentiment in Russia by issuing a special video directed at Russia’s ethnic minorities, especially those in Dagestan, one of the country’s poorer regions in the North Caucasus.

“You do not have to die in Ukraine,” he said, wearing a black hoodie that read in English “I’m Ukrainian,” and standing in front of a plaque in Kyiv memorializing what he called a Dagestani hero. He called on the ethnic minorities to resist mobilization. (AP)