A Ukrainian official said the people killed were waiting in cars to cross into Russian-occupied territory so they could bring family members back across front lines and to safety.
The strike left deep impact craters and sent shrapnel tearing through the the convoy of lined-up vehicles, killing their passengers.
ITV News witnessed the aftermath of the horror attack.
Here ITV News Correspondent John Ray provides a first-hand account from the scene in Zaporizhzhia.
It’s a desperate and distressing scene.
A convoy of wrecked cars, windows smashed, sides punctured by shrapnel.
Inside one van lies the body of man, someone’s father or husband, son or brother.
A mobile phone rings. Perhaps an anxious relative is calling.
There are more bodies lying where they died.
Three missile strikes this morning killed two dozen people and left dozens more wounded.
A survivor tells us she lived because she had stepped away from her car the moment the first missile landed.
"People who stayed in their vehicles had no chance," says Katia.
She was returning to her home across the front line after visiting family.
Others were taking aid to Russian controlled territory and planned to return with relatives.
Olexi is a police officer who was on duty, at the place regularly used as a gathering point for convoys of civilians crossing the front line.
His face is bloodied and bandaged.
"I have no words for what happened, just horror," he tells me.