Serbian President Aleksandar Vucic claimed Serbian authorities discovered "an explosive of devastating power" near a gas pipeline connecting his country to Hungary, leading Hungarian Prime Minister Viktor Orban to imply, without directly attributing blame, that Ukrainian saboteurs were responsible, Politico reported on April 5. Serbia's intelligence chief later said Ukraine, which denied involvement, was not responsible, and Orban's main political rival, Peter Magyar, alleged the incident was staged.

Serbian authorities said they found two backpacks with explosives near the Balkan Stream pipeline — an extension of the TurkStream pipeline — near the village of Tresnjevac in the northern Kanjiza border district. The Balkan Stream-TurkStream pipeline route brings Russian gas across the Black Sea to Turkey and onward through southeastern Europe, and it is the only currently operational route bringing Russian gas to Hungary. Ukraine and Hungary have traded allegations since a Russian strike in late January damaged the Druzhba pipeline carrying Russian oil to Hungary and Slovakia via Ukraine, with Budapest accusing Kyiv of slowwalking repairs.