March 12 (UPI) — Law enforcement officials in New Mexico said they’ve been searching for a 68-year-old retired U.S. Air Force major general who was reported missing last month.

William “Neil” McCasland was last seen at his Albuquerque home Feb. 27, the Bernalillo County Sheriff’s Office said in a post on Facebook. The department issued a silver alert searching for the man, saying it wasn’t clear what kind of clothing he was wearing nor what direction he might have traveled.

“Due to his medical issues law enforcement is concerned for his safety,” the sheriff’s office said.

The FBI’s Albuquerque field office said it was unusual for McCasland to be out of touch from his family for this length of time. The FBI said it believes he left his home on foot and doesn’t expect foul play.

“We are, however, utilizing all possible resources including advanced technologies, and still considering all possible scenarios as we follow up on leads towards locating Neil,” the FBI said in a Facebook post on March 6.

The sheriff’s office said it had searched McCasland’s neighborhood, speaking to more than 600 homeowners in the area.