An Iraqi government official has accused the self-proclaimed Islamic State of Iraq and al-Sham (ISIS) of destroying a historical church in Mosul early on Monday.Dureid Hikmat Tobia, the adviser for minorities of Ninawah province's governor, told The Anadolu Agency that ISIS blew up St. Markourkas church -- a 10th century Chaldean Catholic building.ISIS also bulldozed a graveyard attached to the church on a nearby hill, Tobia added.The Chaldean Catholic Church is made up of Assyrian people in Iraq whose language is Syriac, which is also used as the church's liturgical language.This is not the first time that the extremist militants have desecrated Christian graves in Mosul, according to Tobia.ISIS recently destroyed the ancient city of Nimrud in Iraq. UNESCO director general Irina Bokova has described the incident as a "war crime".The purported incidents follow a video released by ISIS militants showing the extremist fighters purportedly destroying ancient artifacts in Mosul's museum on February 27. The monuments dated back to the 8th century B.C.Iraq has plunged into a security vacuum since June 2014, when ISIS stormed the northern Iraqi province of Mosul and declared what it called a caliphate in Iraq and Syria.