Updated

Ten of 17 Afghan military deserters who walked away from a training program on a U.S. Air Force base in Texas remain at large, sources close to the situation told Fox News on Friday, and seven of the men have been accounted for.

The 17 deserters went AWOL from Lackland Air Force Base, where foreign military officers who are training to become pilots are taught English, according to a "Be-on-the-Lookout" (BOLO) bulletin issued on Wednesday.

Sources said that as of November 2009, one of  the deserters was in Canada, one is now a lawful permanent resident in the U.S., one has left the country and another four are in federal custody and in removal proceedings. The other 10 remain unaccounted for.

On Wednesday night, the BOLO bulletin listing all 17 deserters was distributed to local and federal law enforcement officials and joint terrorism task force members across the country.

The Afghan officers and enlisted men have security badges that give them access to secure U.S. defense installations, according to the lookout bulletin, "Afghan Military Deserters in CONUS [Continental U.S.]," written by Naval Criminal Investigative Service in Dallas and obtained by FoxNews.com.

The Afghans were attending the Defense Language Institute at Lackland Air Force Base in Texas. The DLI program teaches English to military pilot candidates and other air force prospects from foreign countries allied with the U.S.

"I can confirm that 17 have gone missing from the Defense Language Institute," said Gary Emery, Chief of Public Affairs, 37th Training Wing, at Lackland AFB. "They disappeared over the course of the last two years, and none in the last three months."

The most recent Afghan to disappear from Lackland was First Lt. Javed Aryan, who went AWOL in January 2010, Emery told FoxNews.com. The others listed in the NCIS report disappeared at various times last year.

Each of the missing Afghans was issued a Department of Defense Common Access Card, an identification card used to gain access to secure military installations, with which they "could attempt to enter DOD installations," according to the bulletin. Base security officers were encouraged to disseminate the bulletin to their personnel.

"The visas issued to these personnel have been revoked, or are in the process of being revoked. Lookouts have been placed in TECS," it reads.

Treasury Enforcement Communications System (TECS), which is shared by federal, state and local law enforcement agencies, is a computer-based database used to identify people suspected of violating federal law.

Afghans are not the only foreign military who have gone AWOL from Lackland, Emery said.

"In 2009, the Defense Language Institute English Language Center reported two other students from countries other than Afghanistan went missing," he told FoxNews.com. "They include one Iraqi who requested asylum in Houston and one Djiboutian whose status is unknown. To date in 2010, one student from Tunisia and one from Guinea Bissau have gone AWOL in addition to the Afghani student [Aryan] who went AWOL in January.

"To put these numbers in perspective," Emery said, "more than 3,400 international students entered training at DLI in 2009, including 228 from Afghanistan."

A senior law enforcement official said Friday that the Afghans' disappearance was more of an immigration violation than a security threat, saying there are no "strong indications to any terrorism nexus or impending threat."

"A number of these guys have already been located or accounted for by now," the official said. "Some are in removal proceedings to be deported already. (Authorities) still need to locate the others, and that is why the bulletin went out."

The official said the information is "kind of old" -- up to two years -- but added, "It is important in the sense that some people look to come to the U.S. and will take advantage of invitations to train or attend a conference or to study, etc. But their real intention is to get to the U.S. and start a new life. It is not completely rare for this to happen....

"Although we are vigilant and need to work toward not allowing this to happen," the official said, this alert should "not necessarily" be described as "a national security threat, more of a 'hey these guys violated our laws and we need to find them.'"

Fox News has obtained an excerpt from internal emails within law enforcement community relating to the AWOL Afghan soldiers. One email says, in part:

"I just talked to [a special agent] who explained the list was created by him and [another agent]. Both agents compiled the list to identify to the intelligence community the small number of Afghans that have deserted after attending the Defense Language Institute, which is often known as DLI, in San Antonio. They hoped to ensure that anyone who encountered these individuals would be properly notified. The list was created from those who came to the U.S. as far back as 1999, so they did not come in one group. None of the people on this list was identified as having any derogatory information regarding being a national security threat. It is suspected that a small number of those who come to the [DLI] decide to try to make a better life for themselves here so they desert."

Included in the bulletin are photos of the 17 men, accompanied by their dates of birth and their TECS Lookout numbers.

Click here for the names of the 17 Afghan military members named in the alert. 

The bulletin requests, "If any Afghan pictured herein is encountered, detain the subject and contact your local Immigration and Customs Enforcement (ICE) office, the FBI or NCIS."

On Friday, ICE released this statement:

“A routine bulletin was created to inform the U.S. law enforcement community about 17 Afghan soldiers who have deserted in recent years while attending language training at the Defense Language Institute facility in Texas. There is no information that any of these individuals pose a national security threat. Previous indications are that such foreign military deserters typically do so solely for prospects of a better life. This type of bulletin serves to identify foreign military deserters, request investigative leads, and enable ICE to take appropriate enforcement action.”

"When a DLI student goes missing," Emery said, "officials report the incident to the Department of Homeland Security's Immigration and Customs Enforcement as well as the sponsoring service branch. Invitational Travel Orders, passports, driver licenses, and airline tickets are revoked in order to hamper travel opportunities for the missing students."

On Friday, Texas Sen. John Cornyn sent a letter to the secretary of the Air Force demanding answers on the current status of the AWOL Afghans, which he called a breach of national security. Cornyn, a Republican, asked Air Force Secretary Michael B. Donley for an immediate report on the status of the missing men and an assessment of the potential threat to citizens of Texas. He demanded to know why he was not informed about the missing Afghans over the course of the last two years.

The FBI and NCIS did not respond to requests for comment. A Department of Homeland Security spokesman referred FoxNews.com to the FBI.

Mike Levine and Catherine Herridge contributed to this report.