Police have evacuated Serbian Prime Minister Aleksandar Vucic and his family to "a safe location" after uncovering a weapons cache including a rocket-propelled grenade launcher near his home.
Interior Minister Nebojsa Stefanovic said the weapons, which also included hand grenades and rifle ammunition were found in bushes in the neighbourhood of Jajinci, near a crossroads where Vucic's motorcade normally slows down when driving to his home.
The discovery on Saturday, which followed a tipoff police said, exacerbates an already tense atmosphere in the region, which is bearing the brunt of Europe's migrant crisis and where rival Balkan countries which made up former Yugoslavia routinely swap allegations of interference in each other's domestic affairs.
"The Prime Minister is now safe, as well as his family ... it is worrying that weapons were in the place where his motorcade has to slow down to almost 10 kilometres per hour," Stefanovic said.
No arrests have yet been made in connection with the incident, which comes five days after authorities detained a number of people over a suspected plot to sway the outcome of Montenegro's October 16 election and after several mafia-style assassinations among criminal groups in Belgrade.
Serbia is awash with hundreds of thousands of illegal weapons, including assault rifles, anti-tank weapons and explosive ordnance that remained in the private hands after the Yugoslav wars of the 1990s, many of such arms are now in the hands of criminal groups.