Tsunami sirens are still being stolen in Auckland.

Auckland Council has revealed 21 siren units have been stolen from sites across the city since the last update in October.

That brings the total number of thefts to 52 since May last year, with all newly reported thefts reported to Police.

It's suspected the units are being used for 'siren battles'.

Sirening is the subculture that sees music played through loudspeakers attached to bicycles and cars, however it comes out as loud treble.

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