'Price of War': These empty strollers represent children killed during Russian invasion of Ukraine

The sight is peaceful, but its meaning is profoundly sad: 109 strollers, arrayed in neat rows in Lviv's historic Rynok Square. They symbolize a stark tragedy, of the 109 children Ukrainian officials say have died so far in Russia's war on Ukraine.

Lviv Mayor Andriy Sadovyi posted an image and a video of the installation on Friday, urging people to share their own photos of the event.

"This is a terrible price of war that Ukraine is paying today," Sadovyi said. "We call on all adults around the world to stand as one shield to protect Ukrainian children and give them future."

The mayor repeated a call many Ukrainian leaders have made since Russia invaded, asking an international coalition to "close the sky" to Russia's military by establishing a no-fly zone over Ukraine.

Federal prosecutors in Ukraine said on Friday that 109 children have died in the violence, and more than 130 have been wounded. But the prosecutors warn those numbers are preliminary, suggesting the real toll on children has been far higher. It said its staff has not been able to inspect sites where active hostilities are taking place.

The largest number of known child victims are in the Kyiv blast, or province, where 55 children have died, the prosecutors said. Another 34 died in the Kharkiv oblast.

The prosecutors said bombs and artillery shelling have damaged 439 educational institutions, including 63 that were destroyed. Some 126 of those buildings are in Donetsk, the agency said.