Poland has marked the 10th anniversary of the plane crash that killed President Lech Kaczynski and 95 others. A large number of Poles, including President Andrzej Duda, suspect that the crash was not caused by pilot error, as concluded in an investigation by Poland’s previous centrist government, but by foul play. “After 10 years, it’s difficult to say anything or predict whether the case can ever be resolved,” said Duda, after visiting Kaczynski’s grave in Krakow. “We don’t have basic evidence, the wreckage is still in Russia, the black boxes are still in Russia.” Poland’s foreign ministry said in a statement that it had renewed demands that Moscow returned the wreckage of the ageing Tupolev aircraft. “There are no provisions in international law that allow Russia to withhold Polish property,” it said.

Russian authorities said that there is no evidence of an explosion on board the plane, as some in Poland allege. Russia’s Investigative Committee said in a statement that crew errors led to the accident. “The aircraft collided with a tree trunk at a height of about 11m,” it said. “As a result of the detachment of part of a wing, the aircraft began to rotate and after a few seconds fell to the ground in an upside down position.”  President Kaczynsky and 95 highest-ranking officials were on their way to commemorate the Katyn massacre. The Katyn forest, alongside Mednoye, Kharkiv, Bykivnia and Kuropaty, is where a terrifying act of mass executions was carried out by the Soviet authorities in the spring of 1940. It took more than 22.000 lives of prisoners of war and imprisoned civilians, members of the country’s elite.