TUCSON, Ariz. (AP) — Savannah Guthrie said in a video released Monday that her family is “at an hour of desperation” is the search for the “Today” show host's missing mother, ahead of Monday evening's looming ransom deadline set by the purported abductors.

She didn’t mention the deadline in the video, saying her family still believes 84-year-old Nancy Guthrie is out there as the search is now in its second week. There's still no word on whether the 84-year-old is still alive, authorities have said.

The mysterious disappearance and search has riveted the U.S. — from President Donald Trump who spoke with Savannah Guthrie last week to the online sleuths who’ve flooded social media with tips, theories and rumors.

Multiple press outlets have received alleged ransom letters during the past week. At least one letter made monetary demands and set deadlines for receiving the money. The first deadline passed last Thursday but a second one was set for Monday.

Law enforcement officials declined to affirm that the letters were credible but said all tips were being investigated seriously.

Investigators returned to Nancy Guthrie's Arizona neighborhood several times over the weekend, ahead of a Monday evening deadline set by her purported abductors who sent ransom notes demanding money for her return.

Savannah Guthrie said over the weekend that the family was prepared to pay for her mother’s return.

“We beg you now to return our mother to us so that we can celebrate with her,” she said in a video posted Saturday. “This is the only way we will have peace. This is very valuable to us, and we will pay.”

Authorities believe Nancy Guthrie was taken against her will from her home just outside Tucson. She was last seen there on Jan. 31 and reported missing the next day after not attending church services. DNA tests showed blood on Guthrie’s front porch was a match to her and her doorbell camera was disconnected in the early hours of Sunday morning, Pima County Sheriff Chris Nanos has said.

Outside the home on Monday, neighbors strolled by on their morning jogs and walks, while a county sheriff's deputy remained stationed out front.

Detectives and agents carried out follow-up work at multiple locations over the weekend as part of the investigation, the Pima County Sheriff’s Department said Sunday. “Investigators have not identified any suspects, persons of interest, or vehicles connected to this case,” the department said.

Investigators on Saturday were inside daughter Annie Guthrie’s home, about 4 miles (6 kilometers) from Nancy Guthrie's house. On Sunday, an investigator was seen using a pole to search an underground tank behind Nancy Guthrie’s home.

Authorities say they have growing concerns about Nancy Guthrie’s health because she needs daily medication. She is said to have a pacemaker and has dealt with high blood pressure and heart issues, according to sheriff’s dispatcher audio on broadcastify.com.