OAKLAND, CA — Tone testing on individual emergency sirens will begin in Oakland today as part of a citywide upgrade and an effort to ensure proper function, according to city officials.

In December, the city entered into a contract with the company Federal Signal to upgrade and install new sirens, as well as maintain operability. City officials said Oakland utilizes emergency sirens as part of the public safety infrastructure within the city.

The sirens were planned as a result of the deadly 1991 Oakland hills fire and were initially used almost exclusively for fire evacuations.

The system has since been expanded to alert individuals of other major emergencies, such as chemical spills.

From now through the end of April, when the upgrade is scheduled to be completed, the city's emergency sirens will not be used to notify residents and businesses of an emergency. Instead, those in the impact zone will receive a notification by phone, either landline or mobile, via the countywide AC alert system. The alert system has both reverse 911 capabilities and geographic-based telephone targeting.

A full-system test is slated for Feb. 3. For more information about the system, and to sign up for an AC Alert subscription, interested parties can visit www.acalert.org.