KYIV, April 22 (AP) — Satellite images released Thursday showed what appeared to be mass graves near Mariupol, and local officials accused Russia of burying up to 9,000 Ukrainian civilians there in an effort to conceal the slaughter taking place in the siege of the port city.

The images emerged hours after Russian President Vladimir Putin claimed victory in the battle for the Mariupol, despite the presence of an estimated 2,000 Ukrainian fighters who were still holed up at a giant steel mill. Putin ordered his troops not to storm the stronghold but to seal it off “so that not even a fly comes through.”

Satellite image provider Maxar Technologies released the photos, which it said showed more than 200 mass graves in a town where Ukrainian officials say the Russians have been burying Mariupol residents killed in the fighting. The imagery showed long rows of graves stretching away from an existing cemetery in the town of Manhush, outside Mariupol.

Mariupol Mayor Vadym Boychenko accused the Russians of “hiding their military crimes” by taking the bodies of civilians from the city and burying them in Manhush.

The graves could hold as many as 9,000 dead, the Mariupol City Council said Thursday in a post on the Telegram messaging app.