Diplomatic tension has flared between Romania and Hungary over a tense standoff between the ethnic Hungarian and Romanian inhabitants of two neighbouring counties in central Romania.

Two regional councils, one dominated by ethnic Hungarians and the other by Romanians have been disputing the right to place crosses for Romanian soldiers in an international war cemetery which contains the remains of soldiers of multiple nationalities from both world wars.

When a group of ethnic Hungarians formed a cordon trying to prevent a group of Romanians from entering the cemetery for a Heroes Day memorial citing legal reasons, a few individuals from the Romanian group pushed through the police cordon to enter the cemetery by breaking the gate. A massive police presence prevented any significant violence, but the local incident quickly became national news as Romania has not registered inter-ethnic incidents for decades.

This rare incident, in which both local authorities accuse each other while being locked in a legal dispute, caused a diplomatic flare up between the two nations.

Attila Korodi, a Romanian MP of Hungarian origin, was at the scene and told Euronews' Budapest bureau there should “not be any commemoration” until disputes have been sorted with regards to who from the Romanian side is buried in the cemetery.

“Setting up the orthodox crosses are illegal; this was declared by several Romanian authorities," he said. "The human chain on Thursday was to enforce this and not let anyone (misuse) arbitrarily the situation."

Korodi said that it was a very controversial situation, that is used for provocation by some extremist groups and Romanian nationalist politicians.

"Romanian people arrived equipped with Romanian flags, mainly radical football ultras. They were spitting, throwing stones, fighting with the police. And they broke the gate after getting into the cemetery by the back door”, he added.

Ethnic Hungarians form a chain to prevent Romanians entering MTI/Veres Nándor

On other side, Romanian voices said the Hungarians had no legal or moral right from preventing the Romanians organising from a memorial for the Romanian soldiers in the cemetery in the first place.

The Hungarian foreign ministry summoned the Romanian ambassador to protest against this incident, but he refused the invitation, which according to the ministry, is unprecedented in diplomacy. Hungary also claims that the Romanian police did not prevent the incident, whereas the Romanian judiciary announced that it opened a criminal investigation against the individuals who broke the gates.

Hungarian Foreign Minister Péter Szíjjártó called his Romanian counterpart, Teodor Meleșcanu, asking him again to stem any provocations and resolve the issue peacefully.

Bucharest, in turn, accused Budapest of fanning tensions by giving a "distorted presentation of the situation" in its public statements and on social media, with the foreign ministry calling for an end to "provocations and the escalation of tensions".

The Romanian Foreign Ministry said that its minister asked his Hungarian counterpart to send a message to the Hungarian community in Romania to avoid any further escalation and that the Romanian authorities took all measures to prevent any further incidents.

According to the Romanian Memories of Heroes Office, there are 149 Romanian soldiers buried in the Uz-valley cemetery and 749 Hungarian soldiers.

The cemetery is at the borders of Harghita and Bákó (Bacău) counties.

[This article was updated to change it from an Austro-Hungarian World War One graveyard to an international war cemetery spanning both wars]