The FBI said Thursday that it is offering a reward of up to $50,000 for information leading to the recovery of NBC's "Today" show co-host Savannah Guthrie's mother, Nancy Guthrie, and/or the arrest and conviction of anyone involved in her disappearance.

Nancy Guthrie, 84, was last seen Saturday night in her home outside Tucson, Ariz., and her family reported her missing around noon Sunday, after a member of her church notified them the following morning that she didn’t show up for Sunday service as she regularly does.

Pima County Sheriff Chris Nanos said on Monday that authorities believe Nancy Guthrie was removed from her house against her will in a “possible kidnapping or abduction.”

Nancy Guthrie "is considered to be a vulnerable adult who has difficulty walking, has a pacemaker, and needs daily medication for a heart condition," according to the FBI.