Pima County Sheriff Gives Update on Search for Savannah Guthrie's Mom

The Pima County Sheriff's Office provided an update on Savannah Guthrie's missing mother, Nancy ... and, while they're clearly working as hard as they can, they've got no new information to share.

Sheriff Chris Nanos led the media briefing about the 84-year-old who was last seen Saturday night at her Tucson, Arizona home.

The sheriff came out to the podium and said the department felt they needed to hold a press conference in order to clear up the confusion in the case caused by numerous media requests ... promising regular briefings moving forward ... with the next set to take place Thursday morning.

Sheriff Nanos once again refused to say if blood was found at the crime scene ... but, he did note Nancy's house was processed thoroughly by officers looking for any evidence that could aid their investigation.

Special Agent John Edwards of the FBI also addressed reporters ... telling people the agency is working the case in close cooperation with local law enforcement.

Authorities have already said they saw concerning signs at Nancy's house after she was reported missing Sunday ... including finding Nancy's DNA inside and the front door kicked in. The L.A. Times reported it was her blood that was found in the house.

Ultimately, the sheriff's office labeled Nancy's disappearance an abduction ... and put homicide detectives on the case. Authorities have made it clear they're in a race against time to find Nancy -- because she's without meds she needs to survive.

Investigators have been looking at registered sex offenders and others in the area while combing through video from cameras at her home, neighbors' residences, local businesses, and traffic lights.

Savannah's been absent from "TODAY" amid her mom's abduction ... though she did thank her fans for their thoughts and prayers during this difficult time.