Big Island police say the Hawaii Island Tsunami Warning Siren system was inadvertently activated on Tuesday.
It happened at around noon while technicians were conducting repairs to the system.
There is no emergency on the Big Island.
The Hawaii Police Department says it deeply regrets any inconvenience or confusion this may have caused and thanks the public for their understanding.
This came a day after the 67-year anniversary of the tsunami in Hilo that killed 159 people.