Five homes were evacuated in the Springtown neighborhood for an hour Friday night after police recovered a grenade there.
A husband and wife were arrested on weapons and threat charges, according to Livermore police.
The Alameda County bomb squad was called in to disarm the device. It's unknown if the grenade was live or inert. Sgt. J.D. Nelson of the Alameda County Sheriff's Department said the device had been modified but they do not yet know whether there are explosives inside it.
Police say they received a call to investigate threats made at 4:30 p.m. The homes in the 1400 block of Aster Lane were evacuated between 8 p.m. and 9 p.m.