Ukrainian President Volodymyr Zelenskiy warned his people early Saturday that retreating Russian forces left mines across “the whole territory,” including around homes and corpses.

He said they had created “a complete disaster” outside the capital Kyiv.

“They are mining the whole territory. They are mining homes, mining equipment, even the bodies of people who were killed,” Zelenskiy said in his nightly video address to the nation.

“There are a lot of trip wires, a lot of other dangers.”

He issued the warning as the humanitarian crisis in the encircled city of Mariupol deepened, with Russian forces blocking evacuation operations for the second day in a row.

Meanwhile, the Kremlin accused the Ukrainians of launching a helicopter attack on a fuel depot on Russian soil.

Ukraine denied responsibility for the fiery blast, but if Moscow’s claim is confirmed, it would be the war’s first known attack in which Ukrainian aircraft penetrated Russian airspace.

“Certainly, this is not something that can be perceived as creating comfortable conditions for the continuation of the talks,” Kremlin spokesman Dmitry Peskov said, five weeks after Moscow began sending upwards of 150,000 of its own troops across Ukraine’s border.

Russia continued withdrawing some of its ground forces from areas around Kyiv after saying earlier this week it would reduce military activity near the Ukrainian capital and the northern city of Chernihiv.

Ukraine’s military said it had retaken 29 settlements in the Kyiv and Chernihiv regions.

Still, Ukraine and its allies warned that the Kremlin is not de-escalating to promote trust at the bargaining table, as it claimed, but instead resupplying and shifting its troops to the country’s east.

Those movements appear to be preparation for an intensified assault on the mostly Russian-speaking Donbas region in the country’s east, which includes Mariupol.