(CNN) -- Stringent restrictions remain in place Monday on about 100 soldiers at a large military base in Washington state after the theft of "sensitive" and valuable "military-grade" equipment.
Members of the Army Criminal Investigation Command are at Joint Base Lewis-McChord trying to find out who is responsible for the missing items, said Maj. Chris Ophardt, a spokesman for the U.S. Army's I Corps that is headquartered at the base and includes the affected unit.
"Hundreds of items" are missing from a vault that is inside a building on the base, the spokesman said. They include things such as scopes and night-vision goggles but no guns or ammunition.
"There are no weapons, and there's no danger to the public," Ophardt said.
After learning of the thefts, the Army decided on Wednesday to put members of the Army's 4th Brigade, 2nd Infantry Division on lockdown, preventing soldiers from making phone calls or leaving the unit's barracks or unit office.
The unit has been home from Iraq since September 2010.
These measures were relaxed somewhat on Saturday, with some supervised visits allowed on a case-by-case basis to deal with personal issues and permission granted to eat at the base's dining facility. Division members, who live either on or off the base, still must sleep at the barracks.
There is no timetable as to when all the restrictions will be lifted, Ophardt said, adding that decision will depend on the investigation.
"(This will) go on as long as we can gain information about the person or persons involved in the theft," said Ophardt, noting no timetable has been set for when the restrictions will be lifted. "This is being taken seriously, so (the military) can get back the equipment that taxpayers paid for."
Military officials did their monthly inventory of the vault in December. They then did another after the holiday vacation and determined that "large amounts" of items were missing -- "immediately" precipitating the lockdown, said Ophardt.
A $10,000 reward has been offered by the Army in the case.
He explained that every unit has its own vault, which in this case has two locks -- one on the vault, and another on the door to an abutting office. It has not been determined whether the missing items were stored properly or if someone was able to get into a properly locked vault and made off with the equipment.
"There are a zillion possibilities," Ophardt said of what might have happened.
The missing items could all "be bought on the civilian market, just one or two generations older," the spokesman said. He added that they have limited use to the public, given the challenges in knowing how to use them and having the right kind of weapon to attach them to.
The restrictions on the soldiers affect only a fraction of those at the expansive Joint Base Lewis-McChord, as none of the other roughly 50,000 people on the grounds about 13 miles southwest of Tacoma are directly affected.