The remains of Iraq's ancient cultures, which survived pillaging by colonial powers, invasions and wars, are at risk of being obliterated by Islamic State militants. The Sunni insurgents' rampage across northern Iraq has included massacres of Shiite Muslims and other minorities. They are also destroying shrines, tombs, statues and monuments they deem idolatrous or un-Islamic, demolishing what's left of some of the world's oldest civilizations, according to Qais Hussein Rashid, director general of Iraq's museums. The looting and destruction is "worse than what happened after the 2003 U.S.-led invasion and the most serious since 1845 when Iraqi antiquities were discovered" by a British-funded expedition, Rashid said by phone from Baghdad. "We're not able to protect these sites. The priority is to protect innocent civilians." U.S. Secretary of State John Kerry, who this month rallied regional leaders behind American military operations to counter Islamic State, is scheduled to attend a meeting in New York to discuss the threat to the country's heritage. More than 4,000 archaeological sites in areas the group controls in Iraq are at risk, including UNESCO World Heritage monuments at Hatra and Ashur, where remains date back 5,000 years. The Assyrian-empire city of Nimrod, whose palaces and temples were protected by colossal stone statues of winged bulls and lions with human faces, stood just to the south of Mosul, which the Sunni group seized in June. More than 600 items of gold, jewelry and precious stones found there in the late 1980s are commonly referred to as Iraq's crown jewels. Tikrit Castle The militants of the al-Qaeda breakaway group have taken their war on Iraq's rich history further south. Last week, they bombed a fortified site in Tikrit linked to 12th-century wars against Christian armies. "We had only excavated one percent of it," Rashid said of the ruins in Tikrit, birthplace of Salahddin Ayubi, the Muslim conquerer of Jerusalem also known as Saladin, and former Iraqi dictator Saddam Hussein. "It's a huge loss." In Mosul, a shrine and pilgrimage site said to house the remains of the prophet Jonah, swallowed by a whale in Biblical and Koranic stories, was blown to dust in July, Abdulameer al-Hamdani, an Iraqi archaeologist, said. "This wave of destruction in the north is unprecedented," al-Hamdani, who served as an inspector of antiquities in southern Iraq until 2010, said by telephone. Peacock Angel Statues dedicated to renowned musicians and poets, including one to poet Abu Tammam who died in Mosul in 845 A.D., have been targeted. So have Christian churches and temples of the Yezidis, a minority that worships a chief deity known as the Peacock Angel and who were driven from their homes near Mosul by Islamic State. The group's leader, Abu Bakr Al-Baghdadi, has declared a caliphate in parts of Syria and Iraq he controls. Followers believe they are returning to the religious way of life practiced during the lifetimes of Prophet Muhammad and the early caliphs. The group's cultural vandalism is an echo of that of the Taliban, which blew up two giant Buddha statues in Afghanistan's Bamiyan Valley in 2001, and Ansar al-Dine which destroyed Sufi-Muslim shrines in Timbuktu in 2012. After seizing Mosul, Islamic State outlined strict rules on clothing and behavior, and declared a war on the worship of false idols. Nimrod Executions "After Friday prayers, they decide what needs to be destroyed and they go out and do it," al-Hamdani said, citing accounts from colleagues in the region, and government and media reports. "Nobody can check the situation because it's too dangerous." Executions are being staged at Nimrod, and the museum in Mosul has become an Islamic State command center, Rashid said. What it's not obliterating, Islamic State is hoping to sell. "This is a golden time for looters in the whole region, because of the chaos," said al-Hamdani. In the aftermath of the 2003 U.S. invasion of Iraq, about 150,000 items of historical value were stolen, most of which were recovered. Iraq has sent a list of antiquities to border checkpoints and asked Interpol to help monitor known black-market centers. "We hope the anti-Islamic State coalition will speed things up so we can save what we can," said Rashid. "Our Iraqi heritage is on the brink."