Four former employees of the US security company Blackwater have been convicted of almost every charge related to the shootings of more than 30 unarmed Iraqi civilians in Baghdad, seven years ago.

The jury in Washington found Nicholas Slatten guilty of first-degree murder, and the three other ex-security guards - Paul Slough, Evan Liberty and Dustin Heard - were convicted on Wednesday of committing multiple counts of voluntary manslaughter at a Baghdad traffic circle in 2007.

The trial focused on the killings of 14 Iraqis and the wounding of 17 others.

The shootings, which came in the fourth year of the US military invasion of the country, triggered an international uproar over the role of defence contractors, who were hired by the US State Department to protect American diplomats in the Middle Eastern country.

The four men were charged with a combined 33 counts in the shootings, and the jury is expected to continue deliberating on the other counts.

However, Al Jazeera's Rosiland Jordan, reporting from Washington, noted that "even though the men were convicted, the sentencing has not yet been settled".

"They [convicts] plan to appeal the verdicts," she said.

"The end of the legal saga is not yet in sight."

Legal battles

The case was mired in legal battles for years, making it uncertain whether the defendants would be tried.

There was sharp disagreement over the facts in the case.

The defendants' lawyers said there was strong evidence the guards were targeted with gunfire from fighters and Iraqi police, leading the Blackwater employees to shoot back in self-defence.

However, federal prosecutors said there was no incoming gunfire and that the shootings by the guards were unprovoked.

One of the government witnesses in the case, Blackwater guard Jeremy Ridgeway, pleaded guilty to killing an unarmed Iraqi mother sitting in the passenger seat of a car driven by her son.