The 18-year-old student killed himself after firing multiple gunshots at Jeremiah Small, a teacher at the Classical School of the Medes in Iraqi Kurdistan's second largest city of Sulaimaniyah.

"A student killed his American teacher by shooting him dead," said Sulaimaniyah police spokesman Lieutenant Sargut Ahmed.

The student then shot himself dead, according to Sulaimaniyah provincial health chief Raykot Hama Rashid.

Teachers at the school and eyewitnesses reported that Small and the student, who was Muslim, had arguments over religion.

Servant Group International (SGI), which provides teachers for Christian schools in north Iraq, described Small as a "beloved teacher and friend."

"His love for his students extended beyond the classroom, and he regularly led hiking trips, camping trips, and other outdoor activities with the students," SGI said in a statement.

"He was a learned colleague to the teachers in the school and a friend of everyone at SGI."

The statement said it had no further information about the incident.

The Medes School describes itself on its website as a private Christian network of schools in Iraq's Kurdish region that teaches in English.

"We have heard reports regarding the shooting of a teacher in Sulaimaniyah and are working through our consulate in Arbil and Iraqi authorities to ascertain the details of the incident," said a US embassy spokesman in Baghdad.

"At this time, we are waiting for identification to be completed and for the family to be notified."