Greek riot police fired tear gas at protesters near Lake Prespa where the ceremony for the Greece, FYROM agreement took place on Sunday morning.
Opponents of the deal gathered near the village of Psarades waiving Greek flags and shouting slogans accusing the government of treason for accepting the term Macedonia to be used by FYROM.
According to reports, police used tear gas to disperse the crowd when some tried to break through the police cordon and approach the village.
No injuries have been reported.
Dozens of coaches with protesters from Thessaloniki had earlier arrived in the area.
A similar rally took place in central Athens on Saturday. Riot police fired tear gas as some protesters tried to approach the main parliament building where a debate on a non-confidence motion was taking place.
In Greece, there is anger over the government’s acceptance that its neighbor will be able to refer to its language and ethnicity as “Macedonian”.
Tsipras’ domestic critics say he has bargained away Greece’s diplomatic advantages — the power of veto over EU and NATO accession — for a deal that could backfire.
“There is no chance that those speaking a ‘Macedonian’ language will be called ‘North Macedonians’,” said New Democracy leader Kyriakos Mitsotakis.
“We will not divide the Greeks in order to unite the (Macedonians),” he said.