The Islamic State group said today that a US citizen carried out a suicide attack against Iraqi forces involved in an operation to retake the jihadist-held city of Tikrit.
"The brother Abu Dawud al-Amriki (may Allah accept him) launched himself with his explosives-laden truck against a gathering" of Iraqi forces and militiamen, an IS radio bulletin said.
The report gave no details on the man's identity.
It claimed that dozens of Iraqi forces were killed and wounded in the blast, but did not provide further details, such as pictures or footage.
There was no immediate confirmation of the attack from other sources.
Pro-IS social media accounts said the attack was carried out Monday near Samarra, the other main city in Salaheddin province.
Samarra is controlled by the government and has been launch pad for a broad military operation officially launched Monday to wrest back Tikrit, further north up the Tigris River, from the jihadists.
Army commanders say the jihadists have been hampering the advance by resorting to guerrilla tactics, such as car bombs, booby traps and sniper fire.
The jihadist group, which took control of swathes of Iraq last year and also holds parts of Syria, frequently uses foreign fighters for suicide missions.
Track Latest News Live on NDTV.com and get news updates from India and around the world