MITROVICA -- On a winter night in Kosovo, when most people in northern Mitrovica are sleeping, warning sirens installed by Serbian municipal officials suddenly begin to blare.
Within minutes, scores of Serbian men are out in the street. Mobile phones start ringing as former Serbian Interior Ministry police in northern Kosovo's so-called Civil Protection Force shout instructions about where the crowd should go.
The sirens -- along with barricaded streets and daily power cuts -- are examples of the peculiarities that have become a normal aspect of life within the 5-square-kilometer patch of urban landscape that is northern Mitrovica.
The Ibar River cuts through Mitrovica, dividing ethnic Albanians to the south and ethnic Serbs who have clustered together to the north since the end of the Kosovo war in 1999.
Including villages and other small towns north of the river, about 40,000 ethnic Serbs live in Kosovo to the north of the river.
Political leaders of northern Kosovo's Serbs, like Marko Jaksic and Milan Ivanovic, refuse to recognize Pristina's 2008 unilateral declaration of independence. They insist that Kosovo will always be part of Serbia.
On this occasion, the sirens have gone off at 3:40 a.m. because NATO-led Kosovo Force (KFOR) troops are trying to dismantle a barricade built at Rudare about 8 kilometers north of Mitrovica.
The barricade blocks the route to the contested Jarinje customs checkpoint -- a flashpoint of conflict between local Serbs and international forces at the northernmost tip of Kosovo on the road leading to Raska, Serbia.
Such barricades are watched around-the-clock by the men in the Civil Protection Force, who receive Serbian-dinar salaries from Belgrade worth just over $500 a month.
Barricades erected by Serbs on the north side of the central bridge in Mitrovica prevent cars from crossing.
At Rudare, the pile of earth and stones prevents members of the Kosovo Police Force who live in southern Mitrovica from driving to the customs checkpoint. Instead, they must travel to work by helicopter.
In the darkened streets of northern Mitrovica, the word spreads quickly: "Rudare."
Organized Serbian protesters have clashed there in the past when Kosovo Police and KFOR troops have dismantled barricades only to see them quickly rebuilt.
Within two hours, as the sirens wail, KFOR soldiers manage to remove the Rudare barricade again. But by the next day the Serbs have built new roadblocks nearby.
Cut Off In Kosovo
Meanwhile, the Kosovo customs checkpoint is also working, and that has real-life consequences for Serbs trying to make ends meet in northern Mitrovica.
One of them is Blagitse Inackovic, a 44-year-old former office worker laid off from Mitrovica's Trepca mining company in 1999 -- along with 23,000 others on both sides of the Ibar River -- when the firm halted most operations.
The unemployment benefit in dinars that Inackovic receives from Belgrade each month is not enough to feed her two children and pay for their college educations. So Inackovic and her husband, also a laid-off Trepca worker, run a fruit and vegetable stand in northern Mitrovica where they accept both dinars and euros, the official currency used in the south.
Inackovic's worries multiply on market day, the Saturday after the latest incident at Rudare.
Her son Zoran is stopped by customs officials as he tries to bring a fresh supply of produce from central Serbia through the crossing. By the time he arrives with the delivery, market day is over. Inackovic explains that by Monday, when she opens her small business again, the perishables will no longer be fresh and will be difficult to sell.
Members of the Kosovo Police Force stand guard on the central bridge in Mitrovica.
Inackovic says she lives in fear when the sirens go off because her son is among those who go out to join the crowd. She never knows whether the sirens are signaling another confrontation at the barricades or a clash near the bridges that cross the Ibar River.
"The parents are afraid. It is not safe. We have all those problems. How can we explain it? I mean what are we afraid of? Everything," Inackovic says.
"A few nights ago we had those sirens. We had, I don't know what, at the barricades where the young people go and where they don't even know what's going on."
The de facto partition of Mitrovica emerged in June 1999 during the chaotic days after NATO's air campaign against Serbia. As hundreds of thousands of ethnic Albanian refugees were returning to Kosovo, Serbian houses and businesses south of the river were torched. Most Serbs who lived there fled north.
That's when Serbs erected barricades and informal checkpoints on Mitrovica's three main bridges to prevent ethnic Albanians from returning to homes in the north. Ethnic hatred -- fanned by nationalist extremists on both sides -- was acute and almost tangible in the divided city.
Almost 14 years later, a large pile of stones blocks the north end of Mitrovica's central bridge, topped by banners of the Republic of Serbia. Graffiti on the north side reinforces the message -- declaring "Kosovo Is Serbia" and displaying four Cyrillic letter S's (C's in the Latin alphabet) in the quadrants of a Serbian cross: "Only unity saves the Serbs."
Barricades near the west and east bridges are positioned a few blocks north of the river. The streets between those barricades and the bridges are Mitrovica's only multiethnic neighborhoods. They also are the place where ethnic violence flares up most often.
Many Serbs in northern Mitrovica have not crossed into the southern part of their town since 1999 -- either because they are afraid or they simply have no interest.
Jelena Acic, a 22-year-old biology student who has lived north of the Ibar River her whole life, says she is not afraid to make the crossing. She has crossed the river many times without any problems.
"It's quite difficult for those who have resettled on [the north] side. But for those of us who have been living here for a while, it has become normal in some ways," Acic says. "I have to say that we get used to the situation. Maybe for others it would look different, but we get used to the situation."
A Serbian Orthodox cemetery on a hill to the south of the Ibar River in Mitrovica lies devastated, with hundreds of headstones in shards and the chapel at its center desecrated and burned.
Other Serbs in the north say they only cross the divide to visit the graves of relatives buried in a Serbian Orthodox cemetery just south of the river. Organized groups of Serbs make the journey together a few times a year on religious holidays, traveling together on busses that are escorted by KFOR troops.
But each time they arrive at the cemetery, which is unguarded most of the year and openly accessible from the main highway, they find more tombstones have been vandalized.
Learning To Live Together
Officials in Pristina say tensions in northern Kosovo are fueled by "parallel institutions" -- Serbian government offices funded by Belgrade.
By comparison, Pristina officials say relations have gradually improved between ethnic Albanians and the 80,000 Serbs in scattered enclaves to the south of the Ibar River.
In the mostly Serbian town of Gracanica, just south of Pristina, Serbian residents agree. They say they remain wary about possible drive-by shootings on the highway that passes through their town. But there are no barricades in Gracanica other than coils of barbed wire that top the stone walls around the town's 13th-century Serbian Orthodox church.
Gracanica's Serbs say relations with ethnic Albanians have rebounded in the south since March 2004 and are now much better than in Mitrovica.
Randejl Nojkic heads a branch of Serbia's post office in Gracanica that, under an agreement with Pristina, distributes the pensions and social benefits that Belgrade pays to Kosovo's Serbs, including those in the north.
"The problem started being solved when Albanians and Serbs started doing certain jobs together" within the multiethnic Kosovo Police Force, Nojkic says. "At first, it was just on the periphery. Then they began to work together more within the Serbian community. So in a way, the people began to slowly trust the Kosovo Police Force."
Many Serbs in northern Mitrovica have not crossed into the southern part of their town since 1999.
Oliver Ivanovic, leader of the Serbian Social Democratic Party's provincial committee in Mitrovica, says cultural programs have the best chance of success as the small steps that could start to bridge Mitrovica's divide.
One such program is the Mitrovica Rock School, a Dutch-funded nongovernmental organization with branches on both the north and south side of the river.
Teenagers who study how to play rock music in the program -- both Serbs and Albanians -- had formed a band together at one point. But the glare of the media spotlight brought pressure on them from both communities, making it impossible to play together regularly or to tour in Kosovo.
Now, although they live only a few hundred meters apart on opposite sides of the river, the Mitrovica Rock School's ethnic Serbian and Albanian teenagers have to wait until they all travel to a summer camp in Skopje, Macedonia, to play music together.