Russian soldiers stationed in Ukraine at the Chernobyl nuclear plant seem to have had a laissez-faire attitude.

The plant has been contaminated with radioactivity since 1986, when it was the worst-ever nuclear disaster. The first day of the Russian invasion of Chernobyl caused international concern. Russia retreated from the areas surrounding Kyiv last week.

The chief safety engineer at Chernobyl told The New York Times that Russian troops who took over the plant came and did whatever they wanted. The Russian military brought their own experts to the plant, but their advice was not always taken into account.

Russian troops camped out in the radioactive forest for weeks, but there have not been confirmed cases of radiation sickness, The Times reported, adding that some health impacts of nuclear exposure can take years to appear.

A Russian soldier picked up a radioactive substance with his bare hands.

—Defence of Ukraine (@DefenceU) April 6, 2022

Ukrainian officials shared video on Wednesday that they said showed Russia digging trenches in Chernobyl, calling it a complete neglect of human life.

The International Atomic Energy Agency launched an investigation after the state power company of Ukraine said that Russian troops had dug trenches and experienced signs of radiation sickness.