When Putin's bombers flew over Mariupol, something strange was on the ground.

Outside the city's theatre, where hundreds of people were hiding in terror, someone painted a giant plea for mercy:

"CHILDREN"

But Putin's killers bombed them anyway. 600 women and children were murdered.

They've also bombed schools, hospitals, playgrounds, and a mall -- experts are now warning of genocide. We can't let Putin and his killers get away with it, so here's the plan.

Throughout the war, Ukrainians have recorded the atrocities, photographing mass graves, bodies lying in gardens, and babies in the rubble. Now an award-winning team of war zone investigators and legal experts could start verifying that data as evidence to prosecute war crimes. But there's a mountain of it, and they need urgent funding to get the job done.

And there's more: The International Criminal Court is appealing for war crimes witnesses to come forward. Avaaz has over 900,000 members in Ukraine and many could have valuable evidence -- so we'll connect them to investigators, all while powering our campaigns to protect civilians in Ukraine and beyond.

This is our chance to be part of the biggest prosecution of war crimes in history. Let's get started right away -- donate what you can now.