AT&T said on Wednesday that the company is offering up to $250,000 for information leading to the arrest and conviction of those responsible for "fiber vandalism across Alameda County."
Most recently, AT&T spokesman Jim Greer said that vandals cut fiber in two different manholes about 10:30 p.m. Monday at Altamont Pass and Carroll Road in Livermore, causing Internet service to go out. On Wednesday morning, crews had restored all service and the road had been re-opened.
This vandalism is one of at least a dozen fiber-optic cable cuts in Northern California in the past year, the FBI announced in July.
That's when someone sliced at least three fiber-optic cables in an underground vault in Alameda County, which disrupted Internet and phone service around Sacramento for 20 hours before service was restored.
The FBI says fiber cables in Fremont, Berkeley and San Jose have been intentionally severed in 11 instances since July 2014.
Federal officials say there is no evidence that the San Francisco Bay Area acts are linked with the sabotage of a Pacific Gas & Electric Co. substation in April 2013. The nighttime attack knocked out phone and emergency 911 service in Silicon Valley.
NBC Bay Area's Alan Waples contributed to this report.