Washington: A former US Navy SEAL sniper credited with killing more than 150 insurgents in Iraq has been shot to death at a firing range in Texas.

The death of Chris Kyle, 38, was confirmed by FITCO Cares, a foundation he helped start that worked with returning soldiers to help them cope with post-traumatic stress disorder.

Kyle died on Saturday at a firing range in Glen Rose, Texas, while helping a soldier recovering from the condition, an ABC affiliate in Dallas, WFAA-TV, reported. A neighbour of Kyle was also killed.

A suspect has been arrested, and was identified as 25-year-old Eddie Routh. WFAA-TV quoted investigators as saying Routh is a former Marine who is believed to suffer from PTSD.

Kyle served four tours of duty in Iraq from 1999 to 2009, and received numerous honours.

He wrote a best-selling book called “American Sniper.” In it, he says his record as a sniper prompted Iraqi insurgents to put a price on his head.

In a 2012 interview with Time magazine he was asked what went through his mind when he aimed at a target, Reuters adds.

“The first time, you’re not even sure you can do it,” he said. “But I’m not over there looking at these people as people. I’m not wondering if he has a family. I’m just trying to keep my guys safe. Every time I kill someone, he can’t plant an IED. You don’t think twice about it.”

Kyle is the co-author of another book coming out in May under the title “American Gun - A History of the US in Ten Firearms.” For the book he fired 10 weapons - such as the Spencer repeating rifle from the Civil War, the Colt .45 used in the Old West and the Thompson sub-machine gun popular with law enforcement and gangsters in the 1920s - and discussed their parts in US history.

In the wake of the slayings of 20 children and six adults at a school in Newtown, Connecticut in December, Kyle was interviewed in January about rising calls for curbing gun violence in the United States. He told the website guns.com that he favoured arming teachers who have been screened and trained and spoke against restrictions on gun owners.