The U.N. Working Group on Enforced or Involuntary Disappearances is pressing governments to provide information about open cases. Over the past two decades, it received nearly 54,000 cases, of which nearly 43,000 in 84 states remain unsolved. The number of cases is believed to be only a fraction of those who disappeared after being taken by security forces.
OPEN CASES (as of 2012)
Iraq — 16,401
Sri Lanka — 5,676
Argentina — 3,271
Algeria — 3,005
Guatemala — 2,899
Peru — 2,371
El Salvador — 2,271
SYRIA (before the outbreak of the March 2011 uprising against President Bashar Assad)
About 17,000 Syrians are believed to have disappeared during a crackdown on dissent by Assad's father and predecessor, Hafez Assad, according to Radwan Ziadeh, a U.S.-based Syrian opposition figure and human rights monitor.
The official toll of those who disappeared during the rule of a military junta in the 1970s is about 13,000, while human rights activists say more than double that number were killed and are unaccounted for.