Security guards in plain clothes clashed briefly with protesters in front of the Serbian Presidency building on Saturday evening during the 1 in 5 Million protest.
A delegation of protesters tried to jump over railings put up around the main entrance to the building to deliver a list of demands to the President but were stopped by security guards who pushed them back across the fence and then prevented others from crossing over.
Protesters argued with the guards before the delegation was allowed to walk to the entrance with the demands.
Protest organizer Srdjan Markovic said that an agreement had been reached with the security guards to allow the delegation to leave the list of demands at the entrance, adding that the guards would not allow them across the fence.
Markovic managed to get over the fence holding the demands but was restrained by several of the men in plain clothes and pushed back over the fence.
Earlier, speakers at the 36th weekly anti-government protest warned that the authorities are disposing of national resources such as rivers, woods and parks.
Actor and Democratic Party (DS) official Branislav Lecic, the formal host of the 1 in 5 Million protests, told the crowd that national resources should not be usurped, adding that the protests will continue until a system is established which will operate in favor of the citizens of Serbia.
A resident of the village of Rakita, whose inhabitants have been battling against the construction of a mini hydropower plant which they say will leave them without their local river, criticized Belgrade residents for not turning out in greater numbers to protest.
A member of the Movement to Defend the Kostunjak forest in Belgrade Goran Ilic said that the construction site in that forest was illegal and added that the authorities have not reacted to the felling of trees there.