Aleppo, Syria, minaret, built in 1090, destroyed by tank fire A fighter with the Free Syria Army (FSA) fires his weapon during skirmishes with government forces in the contested neighborhood in the northern city of Aleppo, Syria, September 12, 2012. UPI/Ahmad Deeb ALEPPO, Syria, April 24 (UPI) -- An iconic minaret in Aleppo, Syria, built in the 11th century, was destroyed by government tank fire, opposition activists said Wednesday. Video posted by the Aleppo Media Center showed a pile of rubble in the corner of the Great Ummayad Mosque where the minaret stood. The mosque dates back to 715, and the minaret, at 45 meters (148 feet), was built in 1090, the British newspaper The Guardian reported. Although the mosque fell into rebel hands last week, Syrian state media claimed the minaret was blown up by Jabhat al-Nusra, a group connected with al-Qaida and fighting alongside the rebels. The Syrian media did not explain why a militant Sunni group would destroy an historic Sunni mosque, the newspaper observed. European Union anti-terror chief Gilles de Kerchove said about 500 Europeans have joined forces in opposition to Syrian President Bashar Assad, the BBC reported Tuesday. Intelligence agencies say they were concerned European fighters in Syria could join groups linked to al-Qaida and return to Europe to conduct attacks, the BBC said. "Not all of them are radical when they leave but most likely many of them will be radicalized there, will be trained," de Kerchove said. And as we've seen this might lead to a serious threat when they get back. British and Belgium authorities are investigating how people are being recruited to join Syrian rebels, the BBC reported. Officials in the Netherlands have raised the terror threat level to "substantial" over concerns of potentially radicalized citizens returning from Syria.