This alert was sent to phones in Hawaii. (Matthew Nelson/The Washington Post)

Emergency alerts sent Saturday to Hawaiians warning of a “ballistic missile threat” were reportedly false, officials said.

Shortly after 8 a.m. local time Saturday, several alarmed Hawaii residents began posting screenshots of alerts they had received reading: “BALLISTIC MISSILE THREAT INBOUND TO HAWAII. SEEK IMMEDIATE SHELTER. THIS IS NOT A DRILL.”

The Hawaii Emergency Management Agency tweeted at 8:20 a.m. local time that there was no missile threat to the state.

The U.S. Navy also confirmed in an email the emergency alerts had been sent in error.

“USPACOM has detected no ballistic missile threat to Hawaii,” U.S. Navy Commander Dave Benham, a spokesman for U.S. Pacific Command, said in an email. “Earlier message was sent in error. State of Hawaii will send out a correction message as soon as possible.”

At 8:45 a.m. local time, an additional alert was sent to Hawaii residents advising them that the first warning had been a false alarm.

“There is no missile threat or danger to the State of Hawaii,” the follow-up alert read, according to screenshots of the message. “Repeat. False Alarm.”

It is unclear how or why the initial alert was sent out, and how many people received it. What was clear was that the first message caused a brief panic, at least on social media, among those who read it and expected the worst.

Today’s alert was a false alarm. At a time of heightened tensions, we need to make sure all information released to the community is accurate. We need to get to the bottom of what happened and make sure it never happens again. — Senator Mazie Hirono (@maziehirono) January 13, 2018

Sen. Mazie Hirono (D-Hawaii) admonished the wayward message and vowed to investigate how it occurred.

“At a time of heightened tensions, we need to make sure all information released to community is accurate,” Hirono tweeted Saturday. “We need to get to the bottom of what happened and make sure it never happens again.”

Sen. Brian Schatz (D-Hawaii) said the false alarm was based on “a human error.”

“There is nothing more important to Hawai’i than professionalizing and fool-proofing this process,” Schatz tweeted Saturday.

Less than two months ago, Hawaii reinstated its Cold War-era nuclear warning sirens amid growing fears of an attack by North Korea. The tests were scheduled to be conducted on the first business day of every month for the foreseeable future.

The tests were an audible example of the growing strife with North Korea, which has spooked other communities in the still-hypothetical line of fire. Guam distributed a pamphlet on nuclear attack preparedness that encouraged people to avoid using conditioner, “as it will bind the toxins to your hair.” A 16-page bulletin released by emergency management authorities in California warned people to beware of radioactive pets.

Brittany Lyte and Cleve R. Wootson Jr. contributed to this article.