BEIRUT — A landmark mosque in Aleppo was burned, scarred by bullets, and trashed — the latest casualty of Syria’s civil war — and President Bashar Assad ordered immediate repairs on Monday to try to stem Muslim outrage at the desecration of the 12th century site.
The Umayyad Mosque suffered extensive damage, as has the nearby medieval covered market, or souk, which was gutted by a fire that was sparked by fighting two weeks ago. The market and the mosque are centerpieces of Aleppo’s walled Old City, which is listed as a UNESCO World Heritage site.
Government troops had been holed up in the mosque for months before rebels launched a push this week to drive them out. Activists and Syrian government officials blamed each other for the weekend fire at the mosque.
Rebel supporters also alleged that regime forces defaced the shrine with offensive graffiti and drank alcohol inside, charges bound to raise religious tensions further in Syria. Many of the rebels are Sunni Muslims, while the regime is dominated by Alawites, or followers of an offshoot of Shi’ite Islam.
‘‘It’s all blackened now,’’ activist Mohammad al-Hassan said of the site, also called the Great Mosque. One of Syria’s oldest and largest shrines, it was built around a courtyard and enclosed in a compound next to the ancient citadel.
Hassan said the army had been using the mosque as a base because of its strategic location in the Old City; he blamed Assad for the destruction. ‘‘He burns down the country and its heritage, and then he says he will rebuild it. Why do you destroy it to begin with?’’ Hassan said in a telephone interview from Aleppo.
Fighting has destroyed large parts of Aleppo, Syria’s largest city with 3 million residents and its former business capital. Activists say more than 33,000 people have died in the conflict, which began in March 2011 and has turned into a civil war.
Five of Syria’s six World Heritage sites have been damaged in the fighting, according to UNESCO, the UN cultural agency. Looters have broken into one of the world’s best-preserved Crusader castles, Crac des Chevaliers, and ruins in the ancient city of Palmyra have been damaged.
Both rebels and regime forces have turned some of Syria’s significant historic sites into bases, including citadels and Turkish bath houses, while thieves have stolen artifacts from museums.
Karim Hendili, a Paris-based UNESCO expert who oversees heritage sites in the Arab world, said Aleppo’s Old City has been hardest hit. The fire that swept through the souk burned more than 500 shops in the narrow, vaulted passageways, destroying a testament to its flourishing commercial history.