A routine National Weather Service test resulted in a false push notification to mobile phones about a tsunami warning, surprising many people on the East Coast who received it Tuesday morning.

Smartphone users with the AccuWeather app – which has millions of users – received a message of a tsunami warning at 8:30 a.m. Though the notification was a test, and the full notification made it clear it was a test, it wasn’t immediately apparent the notification wasn’t real.

The false alert went out along the entire East Coast and Gulf Coast from Maine to Texas, as well as in the Caribbean.

AccuWeather released a statement more than four hours after the alert blaming the mistake on a miscoded test issued by the National Weather Service. However, officials from the weather service seemed to blame the incident on AccuWeather, saying “at least one private sector company” released the agency’s test message as an actual warning.

“The National Tsunami Warning Center at the National Weather Service issued a test message at approximately 8:30 a.m. ET this morning. The test message was released by at least one private sector company as an official Tsunami Warning, resulting in widespread reports of tsunami warnings received via phones and other media across the East Coast, Gulf of Mexico and the Caribbean,” weather service spokesperson Susan Buchanan said in a statement to NPR.

Buchanan did not respond to request for comment from the Portland Press Herald.

In a statement, AccuWeather said it has “the most sophisticated system for passing on NWS tsunami warnings based on a complete computer scan of the codes used by the NWS. While the words ‘TEST’ were in the header, the actual codes read by computers used coding for real warning, indicating it was a real warning.”

“Tsunami warnings are handled with the utmost concern by AccuWeather and it has sophisticated algorithms to scan the entire message, not just header words, as from the time of a warning to the actual event can be mere minutes,” the statement said. “AccuWeather was correct in reading the mistaken NWS codes embedded in the warning. The responsibility is on the NWS to properly and consistently code the messages, for only they know if the message is correct or not.”

AccuWeather says Tuesday was not the first time “legitimate warning coding was embedded erroneously by the NWS and consequently triggered alerts.” In October 2014, AccuWeather advised the weather service in writing about the potential for this problem to be repeated if it was not fixed, according to the company statement.

The National Tsunami Warning Center said it did not issue a tsunami warning, watch or advisory for any part of the United States or Canada Tuesday morning. The center, based in Palmer, Alaska, issues monthly tests to regional weather offices.

Officials said it appeared to be an issue with the Accuweather app. An Accuweather employee said the company will issue a statement later Tuesday.

Susan Faloon, public information officer for the Maine Emergency Management Agency, said her agency received an email from the National Weather Service about a test of the tsunami alert system, then a follow-up email reiterating that there was not an actual tsunami alert in effect.

If there had been an actual tsunami warning, MEMA would have sent out a message through its emergency alert system. That warning cannot be done with the push of one button to avoid alerts from going out inadvertently, Faloon said. The agency did not receive phone calls from people inquiring about the accuracy of the alert sent out Tuesday.

904AM: A Tsunami Warning was mistakenly sent by an app. There is no Tsunami Warning in effect. It was just a Tsunami test message.

— NWS Miami (@NWSMiami) February 6, 2018

We’ve seen reports that some people have received an erroneous tsunami alert. There is NO tsunami threat to Maine. #mewx #nhwx

— NWS Gray (@NWSGray) February 6, 2018

Jeremy DaRos of Portland said the alert made him “jump” because he lives close to the water and was aware of a recent spate of small earthquakes that made the alert seem plausible. He realized the alert was a test after clicking on the push notification for details.

“Looking out the window and seeing the ocean puts you in a different frame of mine when you get a tsunami warning,” he told the Associated Press.

Last month, a Hawaii state employee mistakenly sent at alert warning of a ballistic missile attack on Jan. 13. That alert caused panic on the islands when it took 38 minutes for emergency officials to retract the warning. A week later, a malfunction triggered sirens at a North Carolina nuclear power plant.

Faloon, from MEMA, said despite the spate of recent false alerts, people should still take emergency alerts seriously.

“The unfortunate thing with all these recent incidents is we don’t want people to ignore them in the future,” she said. “Those are still very important messages people should pay close attention to and seek out additional information about from a local news source.”