A FEW years ago, the Serbs used threats and guns to drive Croats out of their homes in the region surrounding Vukovar, in what was then eastern Croatia.
Now the boot is on the other foot. Hundreds of Serb families living in houses once occupied by Croats have been receiving threatening telephone calls from the former owners.
"We have been called several times in the middle of the night and told that our children will be killed," said Mr Darko Kovacevic, a Serb who runs a bar in the main street of Vukovar. "Before the war we Serbs and Croats did manage to get on, but now there is just too much bad blood."
Before the war between Croatia and Serbia in 1991, Vukovar had a mixed population and was a prosperous town. But the scars of battle run deep, and for many of those involved, particularly in the siege of Vukovar itself, the memories are still far too painful for talk of reconciliation.
"The first Croat to come back to this town will be dead. I personally will pull the trigger," said Mr Slobodan Vindik, a Serb veteran of the 1991 conflict in which 90 per cent of Vukovar was destroyed by besieging Serb paramilitaries and the Serb dominated Yugoslav army, and which ended with some 80,000 Croats being forced to flee after Vukovar and the entire eastern Slavonia region fell into Serb hands.
Under the terms of an agreement hammered out alongside the Dayton peace accords last November, eastern Slavonia, the last slice of Croatian territory still held by rebel Serbs, is to be reincorporated into Croatia following a transitional period under a UN military authority.
The plan also envisages the return of all the Croats expelled following the 1991 fighting, ideally in conjunction with the parallel return of the tens of thousands of Serbs who fled to eastern Slavonia from other parts of Croatia over the past five years.
Officials with the 5,000 strong UN force based in Vukovar acknowledge it is a daunting task, but they insist they wish to prevent a rerun of what happened last year when Croat forces retook the Krajina enclave, sparking a mass exodus of Serbs.
"We are slowly trying to rebuild confidence here and to retain the multi ethnic character of the region," said Mr Jacques Klein, the American head of the UN transitional authority. "We will have failed if people leave en masse."
Mutual suspicions abound. Local Serb leaders holding positions in what they still term the "Republic of Serbian Krajina" are horrified at the prospect of the transfer of power to Zagreb and are about to appeal for a one year extension of the UN's 12 month mandate in the region, due to expire in January.