Hungarian Prime Minister Viktor Orban has convened an emergency meeting of the National Defence Council after explosives were found near a pipeline that transports Russian gas to Hungary.

The discovery in a border area of neighbouring Serbia comes as Orban’s party is badly trailing in opinion polls ahead of crucial elections next Sunday.

Opposition leader Peter Magyar accused him of “panic-mongering” orchestrated by “Russian advisers”, days after security experts warned of a possible “false flag” operation that could be blamed on Ukraine.

Orban, an ally of Russian President Vladimir Putin, has resisted EU calls to abandon Russian energy imports since the full-scale invasion of Ukraine.