The photos, released Friday by the space technology company Maxar, come a day after another apparent mass grave site was revealed near the city that has seen potentially tens of thousands of civilian deaths.
Maxar says the latest images were taken between late March and mid-April over an existing cemetery near Vynohradne, Ukraine, approximately 12 km east of Mariupol.
The company estimates the new sets of parallel trenches are about 40 metres long, and were first created just north of the cemetery between March 22 and 29.
The photos show those trenches more than doubled in size between March 29 and April 15.
Maxar said the first trenches near Vynohradne appear to have been dug at the same time as several rows of fresh grave sites at another existing cemetery near Manhush, about 20 km west of Mariupol.
Photos of that site were released on Thursday by the company, which has provided satellite imagery of the Ukrainian battlefield throughout the war.
Mariupol, located in Ukraine’s southeast, has been home to some of the worst reported atrocities in the war so far, including the bombing of a theatre sheltering civilians and the destruction of a maternity and children’s hospital.
Ukraine estimates tens of thousands of civilians have died in Mariupol, once home to 400,000 people. The United Nations and Red Cross say the civilian toll is at least in the thousands.
Russia has denied attacking civilians in the campaign, which began on Feb. 24 after President Vladimir Putin ordered his troops into the country. It has also rejected all accusations of war crimes, and Western leaders have promised to hold Moscow to account.
Mariupol has been a key strategic target of Russian forces since the war began. The port city would allow the Russians to create a land bridge between the Russian mainland and the Crimean peninsula, which Russia annexed from Ukraine in 2014.
A land bridge could be used to quickly and safely resupply Russian troops currently engaged in a major offensive in the eastern Donbas region, home to two separatist movements that Russia has supported since 2014.
Putin claimed victory over Mariupol on Thursday, despite a pocket of Ukrainian fighters that remain holed up inside a steel plant on the outskirts of the city. Ukraine has denied that Mariupol is under Russian control.
— with files from Aaron D’Andrea and Reuters