DENVER (CBS4)– Some people living in Denver may hear additional warning siren testing in addition to the regularly scheduled testing.

The regular monthly test of all city sirens will be at 11 a.m. which consists of a brief sounding of the siren that fades away.

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Shortly after 11 a.m. there will be another full audible test of several individual sirens in the Fort Logan, Bear Valley, Harvey Park and Harvey Park South neighborhoods as part of ongoing testing to verify sound coverage levels.

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The individual siren tests may fully sound for as long as two to three minutes.

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The sirens are only a test. But if those outdoor warning sirens are sounded at any other time it is advised to seek shelter immediately and listen to media for further warnings or instructions.