Several hundred Russian soldiers were forced to hastily withdraw from the Chernobyl nuclear power plant in Ukraine after suffering “acute radiation sickness” from contaminated soil, according to Ukrainian officials.

The troops, who reportedly dug trenches in a contaminated Red Forest near the site of the worst nuclear disaster in history, are now being treated in a special medical facility in Gomel, Belarus. The forest is so named because thousands of pine trees turned red during the 1986 nuclear disaster. The area is considered so highly toxic that not even highly specialized Chernobyl workers are allowed to enter the zone.

Local reports suggest that seven buses with the zapped troops arrived in Gomel early Thursday. Journalists on the ground have also reported “ghost buses” of dead soldiers being transported from Belarus to Russia under the cover of dark.

U.S. intelligence reported Wednesday that Russian forces began withdrawing from the defunct site. Russia said the withdrawal from Chernobyl was part of a pledge to scale back the invasion. But Ukrainian media says it is actually because the troops were “irradiated” from the contaminated soil.

“Another batch of Russian irradiated terrorists who seized the Chernobyl zone was brought to the Belarusian Radiation Medicine Center in Gomel today,” Yaroslav Yemelianenko, who works for the Public Council at the State Agency of Ukraine for Exclusion Zone Management, posted on Facebook. “There are rules for dealing with this territory.”

The Chernobyl facility fell to Russian control on Feb. 24, the first day of the invasion. Workers were on duty for more than 600 hours before being allowed a shift change. International concern grew immediately when Russian troops moved heavy military hardware through the area, kicking up radioactive dust without any protective equipment. Forest fires in the area also raised concern about environmental contamination.

Digging trenches in the forest—considered the most contaminated area of the site—drew widespread ridicule from Ukrainians who work at the site.

The debacle is the latest in a series of missteps by the Russian troops struggling to keep their footing in their increasingly failed war.