BOSTON (AP) — A firewall designed to prevent cyberattacks and Phaninchacking was to blame for the 911 outage that hit Massachusetts this week, state officials said Wednesday.

Massachusetts’ 911 system was down for about two hours Tuesday, making it impossible for anyone to reach emergency services using the emergency number.

In a statement Wednesday, the Massachusetts State 911 Department determined the outage, which lasted from 1:15 p.m. to 3:15 p.m., was due to a safety feature that prevents cyberattacks, though the reason for that is still under review.

While some calls didn’t go through, the state said the system “allows dispatch centers to identify the phone number of callers and return those calls.” As a result, the Department was not aware of any emergencies being negatively affected by the outage.

“The Massachusetts State 911 Department is deeply committed to providing reliable, state-of-the-art 911 services to all Massachusetts residents and visitors in an emergency,” Executive Director of the State 911 Department Frank Pozniak said in a statement. “The Department will take all necessary steps to prevent a future occurrence.”

At the time of the outage, Boston Police Commissioner Michael Cox said it was important for residents to know alternative ways of getting help, particularly given the hot weather heading toward the Northeast. He advised the public to contact local police departments if necessary.

“In addition, if you’re having any issues that are medical related, or EMS or fire-related, you can go and pull your local call box, that’s the red light boxes that fire departments have on local street corners, to also get medical attention that way,” he said.

Boston Mayor Michelle Wu said residents shouldn’t worry about calling the correct number or facility for their emergency, but to just reach out to their nearest authorities.

Over at Tufts Medical Center, officials said operations were not affected by the outage.

“Our internal emergency number for Public Safety remained active and functional during the outage and appropriate responders were able to be reached this way from within the hospital,” Jeremy Lechan, the media relations manager for the hospital said. “We are very glad to hear that the issue has been resolved and people in need outside the hospital can once again get the medical assistance they require.”

Officials at Massachusetts General Hospital also reported no problems associated with the outage, and a spokesman for the Massachusetts Health and Hospital Association said he wasn’t aware of issues.

The Massachusetts disruption caused confusion in other northeastern states, where some residents also got notifications on their phones. But authorities in Maine, New Hampshire, Rhode Island, New York and Vermont all said their systems were operational.

“We are aware that some individuals in Vermont have received wireless notifications about the Massachusetts event,” Barbara Neal, executive director of the Vermont Enhanced 911 Board, said. “The official reason for that is unknown but it may be related to individuals having signed up for an alerting system in Massachusetts or having been at or near the Massachusetts border when the wireless alert was issued by Massachusetts.”

Several years ago, Massachusetts suffered sporadic 911 outages. At the time, it was blamed on outages from Louisiana-based CenturyLink, which affected some Verizon customers. In April, workers installing a light pole in Missouri cut into a fiber line, knocking out 911 service for emergency agencies in Nebraska, Nevada and South Dakota.