President Boris Tadic has become the first Serbian leader to pay his respects to Croatian victims of a notorious 1991 massacre.
During a visit to a memorial to 260 people murdered at Vukovar, Mr Tadic made a statement expressing "apology and regret".
Vukovar was captured in November 1991 after a three-month siege by the Serb-led Yugoslav army.
The victims of the massacre had sought refuge in the town's hospital.
But two days after Vukovar was seized, they were led to the site of a pig farm and shot, their bodies left in a mass grave.
BBC News
