Several thousand supporters of the beleaguered Belarusian opposition marched through the capital on Saturday to mark the anniversary of the Chernobyl nuclear accident and protest an alleged government cover-up of the disaster’s consequences.

Many of the approximately 3,000 marchers expressed particular dismay over the government’s policy of assigning recent university graduates to work in areas contaminated by the 1986 nuclear reactor explosion.

The Chernobyl power plant in Ukraine is just south of the border with Belarus. The explosion spewed a cloud of radiation over much of Europe, and Belarus, downwind from the plant, was severely affected.