"The souks of Aleppo, a maze of vaulted passageways with shops that sell everything from foods to fabrics, perfumes, spices and artisan souvenirs..."

"... are a tactical prize for the combatants. They lie beneath the city's towering citadel where activists say regime troops and snipers have taken up positions."

Ahmad al-Halabi, an activist based in Aleppo, said residents were struggling to control the blaze with a limited number of fire extinguishers and low water supply: "It's a disaster. The fire is threatening to spread to remaining shops," he said. "It is a very difficult and tragic situation there."