The new site was found just outside of the besieged city of Mariupol.
Previous satellite images showed mass grave sites in Bucha and Manhush, which were initially discovered after Russian troops withdrew from the Kyiv region, according to NPR.
The site in Bucha was discovered at the beginning of the month and led to an escalation of rhetoric from President Joe Biden, who referred to the revelation as evidence of a genocide despite the White House’s hesitancy to use the term.
The new trenches are approximately 130 feet long. They were discovered by Maxar Technologies, a space technology company that is assisting the US and Ukraine in their efforts to document suspected war crimes.
“[Ukraine has] collected a group of international allies to assist, and so we are helping in the collection of evidence and the preservation of evidence relating to possible war crimes,” U.S. Attorney General Merrick Garland said during a press briefing.
European officials say the expect Mariupol to fall completely to Russian forces soon. Russia has continuously broken cease fire agreements meant to allow civilians to evacuate from the area and is reportedly not allowing them to leave their homes for food or water.