The Syrian government said it pushed back rebels out of the mosque after the weekend fighting, although activists gave conflicting reports on who controls it.
Rami Martini, chief of Aleppo's Chamber of Tourism, blamed rebels for targeting the city's monuments and archaeological treasures. He said the losses were impossible to estimate because of the fighting in the area, but added it could be the most serious damage since an earthquake in 1830s struck the mosque.
Despite the fire, the structure of the mosque appeared to be intact, although a gate that leads to the ancient market was burned, said Martini, who is specialized in repairing archaeological sites and monuments.
The platform inside the mosque, or minbar, and the prayer niche also were damaged by the fire, Martini said. The wooden minbar is identical to the one burned in Jerusalem's al-Aqsa Mosque in 1969, he said.
Valuables were stolen from the mosque's library, Martin said, including a transparent box purported to contain a strand of hair from the Prophet Muhammad, along with centuries-old handwritten copies of the Quran.
Assad issued a presidential decree to form a committee to repair the mosque by the end of 2013, although it's not clear what such a body could do amid a raging civil war. The mosque's last renovations began about 20 years ago and were completed in 2006.
In other developments Monday:
— The Syria military denied reports by a human rights group that it has been dropping cluster bombs — indiscriminate scattershot munitions — during fighting. The denial came in a statement carried by the state-run SANA news agency.
Allegations that cluster bombs were used are "baseless and are part of media propaganda that aims to divert international public opinion from crimes committed by armed terrorist groups," the statement said.
The New-York based Human Rights Watch on Sunday cited amateur video and testimony from the front lines in making the allegation that Assad's government has been using the bombs that are banned by most nations in what the group said was a new sign of desperation and disregard for its own people.
— The European Union stepped up pressure on Assad's regime, banning Syrian Arab Airlines from EU airports.
At a meeting in Luxembourg, EU foreign ministers added 28 people to those whose assets are frozen and who are denied EU visas. They also froze the assets of two more companies, including the airline.
— The U.N. envoy on Syria, Lakhdar Brahimi, arrived in Baghdad for talks with Iraqi Prime Minister Nouri al-Maliki and other officials on the neighboring country's civil war. Brahimi is touring the region to try to resolve the Syrian crisis.
— Turkey forced a Syrian-bound plane from Armenia to land in order to search the cargo for weapons. The plane, which was carrying aid for Aleppo, was granted permission to fly in Syrian airspace on condition that it could be searched for military equipment, said Turkish Foreign Ministry spokesman Selcuk Unal.
After the search, Turkish Deputy Prime Minister Bulent Arinc said the cargo contained humanitarian aid and was allowed to continue to Syria.
Last week, Turkey forced a Syrian passenger plane traveling from Moscow to Damascus to land in Ankara on suspicion it carried military gear. Russia, which has backed Assad, said the equipment was spare parts for radar systems.
Over the weekend, Syria and Turkey barred each other's commercial aircraft from flying over their respective territories. The bans came after a week of exchanging fire across their volatile border.
— The Turkish government said the number of Syrian refugees in Turkey surpassed the 100,000 mark and that about 7,000 more were waiting at the border to get in.
Associated Press writers Karin Laub, Zeina Karam and Bassem Mroue in Beirut, Albert Aji in Damascus, Suzan Fraser in Ankara and Frank Jordans in Istanbul contributed to this report.
- Live at the GOP convention: Donald Trump...
- No sign of Trump endorsement, but plenty of...
- Trump speechwriter apologizes for Melania...
- Thunderous boos for Cruz for refusing to...
- 17 arrested in flag-burning melee outside GOP...
- Trump's moment: Speech to close GOP...
- Cruz: Not supporting candidate who wages...
- Rupert Murdoch vows Fox News without Ailes is...
- Utah delegates finally stand and cheer... 93
- Utah GOP delegates finally fired up... 74
- Obama rejects Trump depiction of US in... 40
- The day after: Lee defends Cruz at GOP... 32
- Trump speechwriter apologizes for... 27
- Police give all-clear in Munich... 27
- Thunderous boos for Cruz for refusing... 22
- Ohio Mormon offered invocation at... 22