Tens of thousands of people have staged a protest against plans to introduce street signs written in the Cyrillic alphabet for the minority ethnic Serbs of Vukovar, a Croatian town ravaged by Serb rebels at the start of the 1990s war.
Sunday's protest drew some 25,00 people, many of them veterans of Croatia's 1991-95 war.
Some Croats see the Serbian script as a reminder of the suffering of the country during fighting against the Serb-dominated Yugoslav army and Serbian militias during the 1991-95 war of independence, the Reuters news agency reported.
Wearing their wartime uniforms, the protesters demanded that Vukovar - a martyr town that has become a symbol of the war - be exempted from a law requiring the use of Cyrillic where Serbs make up at least one-third of an urban population.
"There's no way that we accept Cyrillic," Dragutin Glasnovic, the organisers' spokesman, told the AFP news agency.
"Vukovar should be treated differently due to a special respect for its victims on which Croatia was founded."
Rebel Serbs opposed to Croatia's bid for independence from Yugoslavia captured Vukovar after a bloody three-month siege, marking the start of the war, which claimed some 20,000 lives.
Many protesters, who arrived from all across Croatia, wore T-shirts with the inscription "For a Croatian Vukovar - No to Cyrillic" and chanted the town's name.
A giant banner reading "Vukovar will never be Vukovar (in Cyrillic)" was hoisted in Zagreb 's main square. No incidents were reported at the hour-long gathering, police said.
Although they speak practically the same language - it was known as Serbo-Croatian before the war - Croatians use the Latin alphabet while Serbs mostly use Cyrillic.
Serbs are Croatia's largest minority, making up around four percent of the country's population of 4.2 million.
Ethnic minorities have the right to use their respective languages for official purposes such as the names of public institutions or streets in areas where they make up more than a third of population.
Ethnic Serb minorities cross this threshold in Vukovar and around 20 other Croatian municipalities, according to a 2011 census.
The government has repeatedly said it would proceed with its plans to introduce Cyrillic on signs in Vukovar, but veterans threatened that they would remove them by force.
In February, some 20,000 people protested in Vukovar itself.