BEDFORD, Va. — Armed with what one official described as new information, federal and state authorities searched a site on a Virginia mountain Monday for the remains of two Maryland sisters who disappeared 40 years ago.

Bedford County Sheriff Mike Brown said at a news conference that the "forensic dig" on Taylor's Mountain could take a couple of days. He said a Federal Bureau of Investigation evidence recovery team, a Radford University forensic pathologist and state and local authorities were involved in the search for the remains of 10-year-old Katherine Lyon and 12-year-old Sheila Lyon.

Brown said new information prompted the dig, but he declined to be specific.

Asked if it appears human remains will be found, Brown said: "We would hope so."

The Lyon sisters disappeared in 1975 after walking to a shopping mall in Wheaton, Maryland. A search for clues has been ongoing since September on Taylor's Mountain in the Thaxton area of Bedford County.

Authorities have named Richard Allen Welch Sr. and his nephew, Lloyd Lee Welch, as persons of interest in the case. Montgomery County, Maryland, Police Chief Russ Hamill said in October that authorities believed that Richard Welch was a security guard in the Wheaton area at the time of the disappearance and that the family owned property in Bedford County. Lloyd Welch is a child sex offender in a Delaware prison.

Neither man has been charged in the Lyon case, but Richard Welch's wife, Patricia Jean Welch of Hyattsville, Maryland, was indicted last month on a charge of lying to a grand jury.

Bedford County Commonwealth's Attorney Randy Krantz urged any residents with information about the case to come forward.

"Our mission focus is to bring these children home if at all possible," Krantz said.