US State Dept. has issued its annual Trafficking in Persons report which shows that Citizens from Nigeria and fur other countries Yemeni, Pakistani, Afghan, Chadian, and Sudanese children were subjected to forced labor as beggars and street vendors in Saudi Arabia, facilitated by criminal gangs.
Unconfirmed reports indicated fewer Yemeni children may have been forced to work in Saudi Arabia during the reporting period.
A 2009 doctoral study submitted to Naif Arab University for Security Sciences concluded Jeddah may be a hub for an international child trafficking network exploiting the Hajj and Umrah visas (visas for religious pilgrimages to Mecca).
You can view the entire report at this link.