NBC anchor Savannah Guthrie's mother has been abducted, sheriff suspects

The mother of US news anchor Savannah Guthrie has been abducted and "didn't go willingly" from her home, Arizona law enforcement officials suspect.

Nancy Guthrie, the 84-year-old mother of the NBC News host, was last seen in her house outside Tucson, Arizona, on Saturday evening. Her family reported her missing a day later.

When authorities arrived, the scene of Nancy Guthrie's property caused "grave concern", Pima County Sheriff Chris Nanos said.

He did not provide a possible motive and, while there was no initial indication Nancy Guthrie could have been targeted because of her name, the sheriff said "we can't dismiss that".

"I believe she was abducted, yes," Sheriff Nanos told CBS, the BBC's US partner. "She didn't walk away from there. She didn't go willingly."

He told CBS that investigators would try to determine if Guthrie was being stalked or harassed. The FBI is helping the investigation, two sources told CBS.

The sheriff offered few details about what he said was still a "very active" investigation, and urged the public to call authorities with any information.

It is not clear what evidence at her home concerned authorities so much.

The Guthrie family previously said in a statement to NBC News: "We can confirm this is a missing persons case, and the family is working closely with local law enforcement."

Searchers were sent home on Monday to rest after looking all night for Nancy Guthrie, who is described as "not in good physical health", but also has no reported cognitive issues, according to Nanos.

They used drones, aircraft, helicopters, heat sensors, and infrared, the sheriff said, adding: "Everything we have, we've thrown at this."

In an earlier press conference, Nanos had said homicide detectives were called to the scene, which he said was not standard protocol in a missing person case.

Nancy Guthrie was last seen at her home after 21:00 local time on Saturday (04:00 GMT on Sunday), Nanos said.

Savannah Guthrie, who hosts the Today show, was not on air on Monday morning.

But her colleagues shared a statement from her, which said: "On behalf of our family, I want to thank everyone for the thoughts, prayers and messages of support.

"Right now, our focus remains on the safe return of our dear mom."

The anchor had been due to co-host the Winter Olympics opening ceremony for NBC on Friday, but it is unclear if she will take part in that coverage.

Representatives for NBC did not immediately respond to requests for comment.