The Bosnian Serb-dominated entity called Republika Srpska and the Republic of Serbia will mark the first joint holiday on Tuesday – the Day of Serb Unity, Freedom and National Flag.

The date, September 15 1918, was chosen because the Salonica front (also known as the Macedonian front) was finally broken through and Serbia, heavily aided by Allied forces, had finally defeated the armies of Germany, Austria-Hungary and Bulgaria, during World War I.

According to Serbia's state-run TV RTS, all the institutions, municipalities and central streets in the RS and Serbia will be decorated by the flag of Serbia.

The holiday will be jointly celebrated in the RS and Serbia as well as all other parts of the world where Serbs live, symbolizing the unity of the Serb people.

On this occasion, the RS President Zeljka Cvijanovic will speak with Serbia's Defence Minister Aleksandar Vulin, the media reported.