Former Navy SEAL Chris Kyle, known as the deadliest military sniper in recent U.S. history and responsible for killing at least 150 people, was gunned down at a firing range in Texas, police said Sunday.

The 38-year-old Kyle was shot to death along with another man identified as Chad Littlefield, 35, on Saturday afternoon at a firing range in Glen Rose, the Texas Department of Public Safety said.

Shortly after the murders, police arrested Eddie Routh, 25.

Kyle was a U.S. Navy SEAL and served in Iraq, where he killed at least 150 insurgents between 1999 and 2009, according to official Pentagon figures, although he claimed he had dispatched more than 250 enemy fighters.

Before leaving the Navy in 2009, Kyle was awarded two Silver Stars and five Bronze Stars for bravery, according to his book "American Sniper," in which he tells about his career as a military sniper.

In the book, published last year and making it onto The New York Times bestseller list, Kyle says that the Iraqi insurgents nicknamed him "The Devil" and placed a bounty on his head.

Last year, in an interview with Time magazine, the former soldier defended his work in Iraq and argued that killing insurgents meant saving the lives of many of his fellow soldiers.

"The first time killing someone, you're not even sure you can do it. ... And then you're double-thinking yourself, can I really do this?" he said in that interview, adding that he only killed people identified as the enemy to keep his fellow soldiers safe.

Kyle worked as a cowboy in Texas as a young man and began firing guns as a boy when his father took him hunting.

When he left the military in 2009 he founded Craft International, a firm that provided combat and weapons training to military, police, corporate and civilian clients. EFE