New satellite images show the construction of another mass grave site in Vynohradne, Ukraine near Mariupol, which remains under siege, Maxar Technologies said Friday.

The big picture: The discovery follows previous satellite imagery showing the construction of mass grave sites in Bucha and Manhush.

Details: The new images reveal that the Vynohradne cemetery has been expanded over the past month and now includes several long parallel trenches that will likely become new gravesites, according to Maxar.

• Each trench is approximately 131 feet (40 meters) long.
• The initial expansion of the trenches occurred between March 22 and 29, around the same time new graves were first being established near the Manhush cemetery on the northwest outskirts of Mariupol.

Context: United Nations human rights chief Michelle Bachelet said Friday that the UN is seeing growing evidence of war crimes in Ukraine as it catalogs a "horror story" of violations perpetrated against civilians.

• Since launching its unprovoked invasion on Feb. 24, Russian forces have "indiscriminately shelled and bombed populated areas, killing civilians and wrecking hospitals, schools and other civilian infrastructure, actions that may amount to war crimes," the UN said.
• The UN Human Rights Monitoring Mission in Ukraine has documented and verified 5,264 civilian casualties — 2,345 killed and 2,919 injured.
• "We know the actual numbers are going to be much higher as the horrors inflicted in areas of intense fighting, such as Mariupol, come to light," Bachelet said.

Go deeper... Dashboard: Russian invasion of Ukraine