ALEXANDRIA, Va. (AP) — A judge ordered jurors Friday to keep deliberating after they said they were deadlocked in a lawsuit alleging a Virginia-based military contractor is liable for abuses suffered by inmates at the Abu Ghraib prion in Iraq two decades ago.

The eight-person civil jury has deliberated the equivalent of three full days in the civil suit in U.S. District Court in Alexandria.

The trial, which began April 15, is the first time a U.S. jury has heard claims of mistreatment brought by survivors of Abu Ghraib.

Three former detainees sued Reston, Virginia-based contractor CACI. They allege the company is liable for the mistreatment they suffered when they were imprisoned at Abu Ghraib in 2003 and 2004 after the U.S. invasion of Iraq.

CACI supplied civilian contractors to work at Abu Ghraib as interrogators, in support of shorthanded U.S. Army soldiers. Abuse of detainees at Abu Ghraib became a worldwide scandal 20 years ago when photos became public showing U.S. soldiers smiling and laughing as they inflicted physical and sexual abuse on detainees in shockingly graphic ways.