French anti-terror prosecutors have launched an investigation after a Ukrainian-Russian man detonated explosive materials in a hotel room north of Paris. A source at the French anti-terrorism prosecutors office (PNAT) said that on Monday night the 26-year-old man was given medical treatment by fire officers in a hotel in the Val-d’Oise, north of Paris, for “significant burns after an explosion”. An initial search of his hotel room led to the discovery of “products and materials intended for the manufacture of explosive devices”, the source said. The man, of Ukrainian and Russian nationality, was still being questioned by police on Wednesday night. The source confirmed that the PNAT, working with France’s domestic spy agency, had opened an investigation into the man, who was suspected of participating in a terrorist conspiracy and bomb plot. The suspected is reportedly from the Donbas region of eastern Ukraine, part of which has been occupied by pro-Russian and Russian forces since 2014. The Ukrainian and Russian embassies in Paris did not immediately respond to requests for comment. Paris Charles de Gaulle airport, which is close to where the man was arrested, said operations had not been affected. France is on maximum threat alert with less than two months to go until the start of the Paris Olympics. The Games will take place against a complex geopolitical backdrop with the wars in Ukraine and Gaza, and pose a major security challenge. Last month French security services said they had foiled a planned attack on the Games with the arrest of an 18-year-old Chechen man allegedly preparing a suicide attack at Saint-Étienne’s football stadium.