A statement said "there are no indications the crash was caused by hostile fire", adding that an investigation is underway.

"One coalition service member was killed and several injured when their aircraft crashed" in Iraq at around 2200 GMT on Sunday, the statement said.

It did not give the location of the crash or identify any of the casualties but said that three coalition members were "evacuated for further treatment", suggesting they were in serious condition.

The crash happened as the aircraft "was conducting a partnered counterterrorism mission," the statement said.

"The deceased service member's name and further details pertaining to the incident will be released by the pertinent national authorities," it added.

The United States leads an international coalition that has targeted the Islamic State group and other jihadists in Iraq and neighbouring Syria since 2014.

The coalition includes Britain, France, Saudi Arabia and Turkey along with Australia, Bahrain, Canada, Jordan, the Netherlands and the United Arab Emirates.

In March seven US troops were killed when their helicopter crashed during a transport mission in western Iraq, near the border with Syria.

Later that month two coalition members -- an American and a Briton -- were killed by an improvised explosive device in the northern Syrian city of Manbij.