Iraq's Interior Ministry has fired or reassigned more than 10,000 employees, including high-ranking police, who were found to have tortured prisoners, accepted bribes or had ties to militias, a ministry spokesman has disclosed.

A soon-to-be-released internal inquiry also details 41 incidents of human rights abuse at the ministry. In one case, four members of the national police hanged prisoners from a ceiling and beat them with sticks in a ministry-run prison known as Site 4, according to the report by the ministry's inspector general.

The United States has pressured Iraq's Shiite-led government to clean up its security forces as they undertake a broad plan to reduce sectarian violence. Sunni politicians have accused Iraq's police of collaborating with Shiite death squads.

More than half of those fired or reassigned since June were found to have militia ties, Jassim Hanoon, the Interior Ministry's deputy spokesman, said in a weekend interview. The investigation is ongoing.

"Maybe we aren't 100% cured," Hanoon said. "But we're getting better day by day." Some ministry employees were fired for arresting innocent people, while others had past criminal records, he said.

Investigators are using information gathered within the ministry to probe political leaders and members of parliament, something not previously done, Hanoon said. Prime Minister Nouri al-Maliki has vowed to pursue criminal charges against political figures — including members of parliament — linked to extremist groups.

U.S. military advisers are working to better screen and train police, including requiring 15 to 20 hours of human rights training for recruits, said Lt. Col. Pablo Hernandez, a spokesman with the U.S. military unit responsible for training Iraqi police.

"If you look at what they had in the past and the product they're putting out today, it's a lot better," Hernandez said.