Branislav Dukic, head of a non-governmental organisation which organised the gathering, said: "Republika Srpska is the most important and sacred Serbian thing on the left side of the Drina [river], as Kosovo is on its right side."

Kosovo's unilateral proclamation of independence from Serbia on February 17 has raised concerns about the future of Bosnia.

Since its 1992 to 1995 war, the former Yugoslav republic has consisted of two largely autonomous entities, the Serb-run Republika Srpska and Muslim-Croat Federation.

The two share weak central institutions, while each has its own government, parliament and police.

Secession threats

Most Bosnian Serbs feel their entity should follow Kosovo's lead and be allowed to secede from Bosnia and eventually be attached to Serbia, which they see as their "motherland".

Addressing the demonstration, Milorad Dodik, the prime minister of Republika Srpska, said: "This is a democratic, human revolt!" This badge that I have on reads 'Kosovo is Serbia' and I will always tell this to everyone."

"The most important answer to the proclamation of Kosovo's  independence is a peaceful and democratic protest," he cited messages from Boris Tadic, Serbia's president and Vojislav Kostunica, Serbia's prime minister as saying.

The protesters waved Serbian flags while some carried pictures of Vladimir Putin, Russia's president, who has strongly opposed Kosovo's independence.

The Bosnian Serb parliament said last week that Republika Srpska should  make a similar move to Kosovo if a significant part of the United Nations and most members of the European Union recognised Kosovo's independence.

Such a move was strongly rejected by EU ambassadors to Bosnia, who underlined that the entities have no right to secede under the peace deal that ended Bosnia's war.