What are those sirens you're hearing in Pierce County?

PIERCE COUNTY, Wash. -- Don't worry, authorities say there is no cause for alarm.

If you've heard emergency warning sirens in the last few days in Pierce County, military officials say it's because of a training exercise at Joint Base Lewis-McChord.

Here's the alert from JBLM:

TRAINING ALERT: Increased C-17 flying activity scheduled for JBLM’s 62nd Airlift Wing training exercise April 9-13

The 62nd Airlift Wing on McChord Field, Joint Base Lewis-McChord, will conduct a training exercise April 9-13.

People on and off base can expect an increased level of aircraft activity during day and nighttime hours. 

Additionally, the use of simulators and other pyrotechnics may be heard. On base residents may also hear the use of the “Giant Voice” public address system on McChord Field.