Vukovar was demolished in attacks by the Serb-led Yugoslav army during the 1991-1995 war in Croatia that killed at least 10,000 people. The conflict erupted after Croatia declared independence from the former Yugoslavia, triggering a rebellion by minority Serbs.
The protesters in Vukovar say people who committed war crimes are still walking around freely. Vukovar Mayor Ivan Penava says "we have failed as a state." Croatian media say conservative Prime Minister Andrej Plenkovic faces pressure from right-wing hardliners in his ruling Croatian Democratic Union party.