BEIRUT • Islamic State in Iraq and Syria (ISIS) extremists have blown up the famous Arch of Triumph in the ancient Syrian city of Palmyra, the country's head of antiquities said yesterday, as the militants press their campaign to destroy the treasured heritage site.

Syrian antiquities director Maamun Abdulkarim warned of impending catastrophe at the Unesco-listed World Heritage site, which the extremists have been tearing down since capturing the ruins in May. "This is a systematic destruction of the city. They want to raze it completely," Mr Abdulkarim told Agence France-Presse.

"They want to destroy the amphitheatre, the colonnade. We now fear for the entire city," he added, calling on the international community to "find a way to save Palmyra".

Both the citadel and the ruins are on the Unesco World Heritage list, and before the war, around 150,000 tourists a year visited Palmyra.

Sunni extremist group ISIS has already destroyed the shrine of Baal Shamin and the 2,000-year-old Temple of Bel, regarded as Palmyra's masterpiece, as part of a campaign to destroy pre-Islamic monuments, tombs and statues it considers idolatrous.

Experts say the militants have used the destruction to raise their profile to attract new recruits, and are also funding their "caliphate" by selling artefacts on the black market.

Syria's archaeology association, Apsa, says that more than 900 monuments and archeological sites have been looted, damaged or destroyed during the four-year civil war.

The Arch of Triumph, situated at the entrance of the ancient ruins' historic colonnaded street, was an "icon of Palmyra", Mr Abdulkarim said, warning that ISIS fighters have already laid explosives at other monuments.

"We have received news from the site that the Arch of Triumph was destroyed yesterday (Sunday). ISIS booby-trapped it several weeks ago," he said.

"We are living through a catastrophe. Since the capture of the city (by ISIS), it has been one shock after another."

The Syrian Observatory for Human Rights monitoring group and local activist Mohammad Hassan al-Homsi backed up the account. "The Arch of Triumph was pulverised. ISIS has destroyed it," he said.

Palmyra's ancient citadel has also been damaged by heavy bombardment from barrel bombs dropped by Syrian government forces, according to experts and activists.

AGENCE FRANCE-PRESSE