Three abducted Americans released by Iraqi militia

Three Americans kidnapped in Baghdad last month have been freed by their Iraqi captors.

The men were said to be in good health and handed over US embassy diplomats in the Iraqi capital, according to officials.

The US state department later confirmed the news and thanked the Iraqi government for their role in securing their release. 

"We sincerely appreciate the assistance provided by the government of Iraq, and its whole-of-government effort to bring about the safe release of these individuals," deputy spokesman Mark Toner said in a statement.

Washington confirmed that several Americans had gone missing in Iraq in January.

Iraqi officials said the three were kidnapped from a "suspicious apartment" in a neighbourhood that was home to both Sunni and Shia Iraqis.

It was believed that an Iraqi Shia militia was behind the kidnapping. 

Many foreigners and Iraqis have been held by militia groups operating in Baghdad, sometimes for ransom but often for sectarian reasons. 

The sense of lawlessness in the capital has undermined confidence in Baghdad's ability to control state-sanctioned militias.

These armed groups, known as the Popular Mobilisation Brigades, make up an important component of the Iraqi armed forces' fight against the Islamic State group.

However, human rights groups have accused the armed groups of a wave of sectarian killings in Sunni areas.