MINNEAPOLIS  When the girl now identified as Jane Doe 2 came under their control in 2006, at age 12, the Somali Outlaws and the Somali Mafia gangs set a firm rule: Their members could have sex with her for nothing; others had to pay with money or drugs.

Repeatedly over the next three years, in apartments, motel rooms and shopping center bathrooms in Minnesota and Tennessee, the girl performed sexual acts for gang members and paying customers in succession, according to a federal indictment that charged 29 Somalis and Somali-Americans with drawing young girls into prostitution over the last decade, using abuse and threats to keep them in line, and other crimes. The suspects, now aged 19 to 38, sported nicknames like Hollywood, Cash Money and Forehead, prosecutors said.

The allegations of organized trafficking, unsealed this month, were a deep shock for the tens of thousands of Somalis in the Minneapolis area, who fled civil war and famine to build new lives in the United States and now wonder how some of their youths could have strayed so far. Last week, in quiet murmurings over tea and in an emergency public meeting, parents and elders expressed bewilderment and sometimes outrage  anger with the authorities for not acting sooner to stop the criminals, and with themselves for not saving their young.