Deprived of foreign assistance, the rebels were quickly routed by the Ottomans, whose units were manned primarily by Albanians and Bosnian Muslims. In early October, Karađorđe fled to the Austrian Empire. He was joined by around 100,000 other Serbs fleeing the Ottoman advance, including 50,000 from Belgrade and its environs alone. Belgrade fell later that month. The city's fall marked the end of the First Serbian Uprising. The Ottomans singled out men and boys over the age of 15 for execution, and sold women and children into slavery. Torture was used extensively and executions were particularly brutal. "Men were roasted alive, hanged by their feet over smoking straw until they asphyxiated, castrated, crushed with stones, and bastinadoed," one eyewitness wrote. "Their women and children were raped and sometimes taken by force to harems. Outside Stambul Gate in Belgrade, there were always on view the corpses of impaled Serbs being gnawed by packs of dogs." Another account relays how infants and toddlers were boiled alive. In one day alone, 1,800 women and children were sold into slavery at a Belgrade market. Churches across the city were destroyed and mosques that had been converted into churches following the city's capture in 1806 were returned to their original use. Others were deliberately torched by the Ottomans for the purpose of inflicting suffering on the city's inhabitants. In one instance, several dozen Serb refugees seeking shelter in a mosque were burned alive inside.