Kosovo, a small landlocked enclave in the Balkans mainly populated by ethnic Albanians, declared independence from Serbia in 2008. Serbia, however, did not recognise the split. Mitrovica, a disputed territory on the border between the two countries, is mostly populated by ethnic Serbs but is controlled by Kosovo.
Both countries are seeking membership to the European Union, but the EU requires there be no territorial disputes between neighbours as one of the main preconditions of joining the bloc. The train sent from Belgrade to Mitrovica last week however almost veered everything off-track.
Why was the train so controversial?
The Kosovo administration viewed the train, which was covered in Serbian nationalist banners and Christian-Orthodox symbols, as a provocative move by the Serbian administration. One of the Serb-nationalist slogans on the train read "Kosovo is Serbia."
Kosovo's President Hashim Thaci, a former fighter against the Serbian army during Kosovo's war for independence, said on his personal Facebook account that granting access to the train violated Kosovo's laws and was "completely unacceptable."
Thaci dismissed Serbian claims that his government was blocking the free movement of people and goods. Serbia's President Tomislav Nikolic went as far as accusing Kosovo of seeking to start "a war" with Serbia, pointing to the presence of Kosovo's Regional Operational Support Unit (ROSU), or local special forces, on the border.
Serbian Prime Minister Aleksandar Vucic, who gave permission for the train to go ahead with its journey, later halted the train at Raska, a border city on the Serbian side, claiming that ethnic Albanians in Kosovo were planning to attack to the train.
Following the incident, ethnic Serbs in Kosovo poured onto the streets and protested against their own country's administration.
Where is Mitrovica and why is at the centre of the dispute?
Mitrovica is technically divided into two by the Ibar river. The northern part of the city hosts a Serb majority, and they have their institutions, local administration, schools and health care system. But Serbia does not have any police and armed forces in Kosovo.
The Kosovar government considers Mitrovica to be part of Kosovo. But Belgrade does not recognise Kosovo as a country and instead says the enclave historically belongs to Serbia.
The city is is valuable for both sides because it is economically important and rich with natural resources.
The Trepca Mining and Metallurgical Complex, which is based in Mitrovica, is a large industrial complex that provided jobs for more than 20,000 people at one time, but is not as profitable as it used to be.
Serbia considers the complex as belonging to a list of "socially-owned enterprises," which last year Kosovo sought to take control of, in order to save it from bankruptcy.
The move ignited protests by Serbs in the country and the Serbian government in Belgrade.
President Nikolic said that Serbia is acting in accordance with its constitution, which states that "Kosovo and Metohija is, under international law, a part of Serbia." But his counterpart President Thaci said on Monday that Serbia is following the same policy as Russia in Crimea, by trying to annex the northern part of Kosovo and provoking a regional war.
Is Mitrovica the problem, or is the independence of Kosovo the problem?
The dispute of Mitrovica is linked with Kosovo's status in international law.
The only document in international law regarding Kosovo's status is UN Security Council Resolution 1244, which was adopted in 1999.
According to the resolution, the UNSC reaffirms the call in previous resolutions "for substantial autonomy and meaningful self-administration for Kosovo."
The International Court of Justice (ICJ) also said in 2010 that Kosovo's declaration of independence "did not violate any applicable rule of international law."
In 2013, Serbia and Kosovo signed an agreement in Brussels aiming to normalise relations.
The Brussels Agreement accepts that Mitrovica is inside Kosovo's borders. However, it gives some privileges to the northern part such as: the police commander should be a Kosovo Serb nominated by the Ministry of Internal Affairs from a list provided by the four mayors on behalf of the local Serb community.
This also applies to other Serb majority municipalities such as Zvecan, Zubin Potok, and Leposavic.
Regarding judicial matters, a division of the Kosovo court of appeal will have a permanent presence in North Mitrovica, consisting mainly of Serb judges.
More than 110 countries have recognised Kosovo's independence. Russia, China, Spain and Greece are among the countries that do not recognise Kosovo's independence.
What can the two countries do to ease tensions?
Bojan Elek, a researcher at the Belgrade Centre for Security Policy, told TRT World that a reintegration policy for the region is not a viable option anymore.
Instead, Elek suggests establishing an "association of Serbian Municipalities in Kosovo, in line with the Brussels Agreement, which should provide some autonomy to Serbs in the north for the price of becoming integrated into institutions in Kosovo."
He also said that political elites should keep away from any provocative statements that could spark conflict and keep "interethnic hatred between Serbs and Albanians" alive.
Arife Muji, a researcher at the Kosovar Center for Security Studies, also told TRT World that both sides should keep all dialogue within the ambit of EU mediation.
"However, such dialogue needs to have a more comprehensive approach by being stricter and having issues tackled more seriously," she said.
Muji also said that the authorities should not promote nationalist declarations which will ignite more violence, otherwise, the "Serbian scenario may have very dangerous consequences" which might resemble the situation in Republika Srpska, which is one of two constitutional and legal entities of Bosnia and Herzegovina.
Author: Ali Topchi