Over 1,500 new graves have been dug at a mass burial site near the Russian-occupied city of Mariupol in southern Ukraine, satellite images of the area show. Thousands of civilians in the port city were killed before the Kremlin completed its capture of Mariupol in May. Now, a BBC analysis of satellite images show that three burial sites around the city have been steadily expanding since the spring. One site at Staryi Krym, northwest of the city, has seen 1,500 new graves dug since June. The U.K.’s Centre for Information Resilience now estimates that 4,600 graves have been dug at the site since the war began in February, though it’s not clear how many bodies are buried there. Ukrainian authorities estimate that 25,000 people died in the fight for Mariupol, including as many as 7,000 killed in rubble as their homes were bombed.