Russian shelling on an aid hub in the town of Orikhiv in southern Ukraine has killed seven people, the emergency services said on Monday.

Regional governor Yuriy Malashko called it a "war crime". "They hit a humanitarian aid delivery spot in a residential area," Malashko said on social media.

"Four people died on the spot: women aged 43, 45 and 47 and a 47-year-old man." The death toll has since increased, emergency services said.

"Rescuers removed the bodies of three people with no signs of life from under the rubble. The number of dead has risen to seven", Ukraine's emergency services wrote on Telegram.

Orikhiv, with a pre-war population of around 14,000 people, is in the frontline southeastern region of Zaporizhzhia, which Russian leader Vladimir Putin claimed to have annexed last year despite not having full military control over it.

Ukraine's prosecutor general said in a statement the strike had occurred a day earlier at 1:20 pm local time (1020 GMT), and that 13 people were injured, in addition to those killed. 

It released images showing a red-brick two-storey building partially collapsed and surrounded by debris and snapped roof beams. Orikhiv is near the front line where Ukrainian soldiers last month were pushing to recapture heavily fortified positions from Russian forces.