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EXCLUSIVE: A book celebrating suicide bombers has been found in the Arizona desert just north of the U.S.- Mexican border, authorities tell Fox News.

The book, "In Memory of Our Martyrs," was spotted Tuesday by a U.S. Border Patrol agent out of the Casa Grande substation who was patrolling a route known for smuggling illegal immigrants and drugs.

Published in Iran, it consists of short biographies of Islamic suicide bombers and other Islamic militants who died carrying out attacks.

According to internal U.S. Customs and Border Protection documents, "The book also includes letters from suicide attackers to their families, as well as some of their last wills and testaments." Each biographical page contains "the terrorist's name, date of death, and how they died."

Agents also say that the book appears to have been exposed to weather in the desert "for at least several days or weeks."

Authorities told Fox News that there were no people in the area at the time the book was found, and no arrests have been made in connection with it.

"At this time, DHS does not have any credible information on terrorist groups operating along the Southwest border," a Department of Homeland Security official said in a statement. "We work closely with our partners in the law enforcement and intelligence communities and as a matter of due diligence and law enforcement best practice, report anything found, no matter how significant or insignificant it may seem."

Statements from U.S. officials, including FBI director Robert Mueller, have raised serious concerns in recent years over "OTMs" -- or illegal immigrants other than Mexicans -- who have crossed the southwest border at alarming rates.

Mueller testified before the House Appropriations Committee in March 2005 that "there are individuals from countries with known Al Qaeda connections who are changing their Islamic surnames to Hispanic-sounding names and obtaining false Hispanic identities, learning to speak Spanish and pretending to be Hispanic."

Just last year, the Department of Homeland Security had in custody thousands of detainees from Afghanistan, Egypt, Iraq, Iran, Pakistan, Saudi Arabia and Yemen. U.S. Border Patrol statistics indicate that there were 108,025 OTMs detained in 2006, compared to 165,178 in 2005 and 44,614 in 2004.

Authorities would not release a picture of the book to Fox News, or reveal how long they believe it was lying in the desert. Immigration officials have previously discovered items along the U.S.-Mexico border from Middle Eastern origin, including Iranian currency in Zapata, Texas, and a jacket found in Jim Hogg County, Texas, that was covered in patches including an Arabic military badge that illustrates an airplane flying into a tower.