Civil Defense sirens throughout the county will be activated at 11:45 a.m. today as part of a test of system upgrades.

The sirens, which warn of approaching enemy attack, tsunamis and other potential disasters, usually are tested statewide on the first working day of the month.

Maui County has approximately 80 sirens, some of which have undergone upgrades in recent months to a radio component in the triggering mechanism, according to Civil Defense administrator Gen Iinuma. The added siren test will allow officials to compare the response of upgraded sirens against the older units, he said.