By Marko Kovac BBC, Dubrovnik

After being heavily shelled during the 1990s conflict that split the former Yugoslavia, Croatia's historic Adriatic town of Dubrovnik is under threat again - this time by the decay of its cultural heritage.

Dubrovnik Cathedral: Sculptures are crumbling

Croatian historians and students have taken up the cause to save their town, urging the UN to come to the rescue of its rotten palaces, ports and cathedrals.

The threat was underlined last month when a large storm caused extensive damage to the town's old port.

One of the oldest pillars in the city, dating back to 15th Century, is cracking up from corrosion.

Sculptures at Dubrovnik cathedral are crumbling away.

Historians, supported by hundreds of students across the country, accuse both the Croatian Government and local authorities of doing too little to safeguard the city's heritage.

Political wrangling

They say their appeal to the United Nations Educational Scientific and Cultural Organisation (Unesco) is Dubrovnik's only chance of survival.

Those who are trying to do something about this decay are being anonymously threatened Goran Vukovic

During the war, Unesco urged the Yugoslav authorities to stop the shelling of the town.

The UN's International Criminal Tribunal in the Hague later included the destruction of historic monuments in its 16-count indictment relating to attacks on Dubrovnik.

The problem now is partly the result of political wrangling, the historians say, which results in neglect.

International hotel chains are ready to move in

The Croatian Government has accused local authorities of misusing the state budget.

But Dubrovnik's mayoress, Dubravka Suica, insists the city is not receiving enough money.

Meanwhile the old city decays.

"There is not enough political will to appoint professional restorers," says art historian Goran Vukovic.

"Even more absurd is that our mayoress has used budget funds to reconstruct her own offices, rather than to save our heritage."

Threats

He claims that people trying to protest about the need for action to preserve the city are frightened of the local authorities.

Some, he says, have been anonymously threatened.

Dubrovnik became an important Mediterranean sea power in the 13th Century.

Although severely damaged by an earthquake in 1667, it managed to preserve its beautiful Gothic, Renaissance and Baroque churches, monasteries, palaces and fountains.

One of Croatia's main sources of income is tourism, in which Dubrovnik, with its famous historic white-stone architecture, plays a key role.

Its popularity has increased in recent years, with property prices spiralling higher and international hotel chains ready to move in.

But decay and erosion could jeopardise Dubrovnik's reputation as first-class tourist destination and - experts say - even its place on Unesco's list of World Heritage Sites.