Two incidents were reported between drivers and protesting farmers blocking roads in the city of Pancevo.
In the first incident, a driver verbally assaulted the farmers whose tractors were parked across a road but left after a shouting match. Police officers posted at the roadblock did not intervene, witnesses said.
In a separate incident, a driver tried to force his way through the roadblock, hurling verbal abuse at the farmers. He picked up a stone and threatened to throw it at the protesters but turned and left after the farmers came up to him.
The farmers have been protesting for days, demanding that the government provide assistance because of high fuel and fertilizer prices and low purchase prices of sunflower and other farm produce.