Authorities have said the midnight broadcast "was only a test"
Some residents in Guam were startled last night when an emergency warning was accidentally played on two radio stations.
The US territory in the Pacific has been at the centre of international attention recently, amid claims by North Korea that they were planning for a potential missile strike targetting the waters near the island.
US authorities have pledged to protect the island - which also houses thousands of US military personnel - while authorities on Guam have issued precautionary guidelines on how to react in the event of a nuclear missile strike.
According to The Guardian, a music station and a Christian network on the island accidentally warned listeners of an unspecified threat at around 12.30am on Tuesday morning local time.
In a statement, Guam's Office of Civil Defence said: "At around 12:35 am, the Offices of Homeland Security and Civil Defense received reports that [broadcasters] KSTO were running a test of the Emergency Alert Broadcast System.
"According to KSTO, this was only a test. There is no official statement or warning from GHS/OCD regarding a threat."
George Charfauros, Guam Homeland Security Advisor, insisted that the threat level had not changed and it remained 'business as usual' on the island.
He said: “Residents and visitors are reminded to remain calm, even with the continued unconfirmed reports throughout the media.
"We continue communication with our federal and military partners and have not received official statement warranting any concern for imminent threat to Guam or the Marianas.”
Meanwhile, state media in North Korea reported that Kim Jong Un has delayed a decision to target the US territory - despite being pictured examining plans to fire missiles into waters near Guam.
South Korea President Moon Jae-in, however, expressed his hope for a peaceful resolution to the growing tensions.