NEWARK, New Jersey — Air traffic control problems continued at Newark Liberty International Airport on Sunday morning after an equipment issue prompted the Federal Aviation Administration to order a 45-minute ground stop at the New Jersey airport, officials said.

The FAA said in a statement that a telecommunications issue at the Philadelphia TRACON (terminal radar approach control) Area C facility, which guides aircraft in and out of Newark, caused the agency to issue a ground stop.

“The FAA briefly slowed aircraft in and out of the airport while we ensured redundancies were working as designed,” the FAA said in its statement.

As of 11 a.m. ET, the FAA said, “operations have returned to normal” at Newark Liberty.

Video in the media player above is from a previous update

On Sunday afternoon, the FAA released updated information, saying an audio issue, not an outage, prompted the ground stop at Newark. The agency said there were popping sounds on an unspecified number of radio frequencies. While air traffic controllers were able to communicate with aircraft, the radio system was not working correctly, prompting the switch to a backup system, the FAA said.

The incident marks the third time in the past two weeks that technical problems have disrupted air traffic at Newark Liberty.

On Friday morning, radar screens at the airport went black for approximately 90 seconds, according to the FAA. During the outage, which occurred at about 3:55 a.m. ET, air traffic controllers could be heard telling a FedEx plane that their screens had gone dark and then asking the aircraft to tell their company to apply pressure to get the problem fixed.

In another transmission, a controller told an arriving private jet that the airport just had experienced a brief radar outage and to stay at or above 3,000 feet in case the controllers couldn’t get in touch during the aircraft’s descent.

The FAA said that the Friday outage stemmed from a “telecommunications outage that impacted communications and radar display at Philadelphia TRACON Area C,” which is the facility that covers the airspace around Newark.

On April 28, an outage at Newark Liberty caused air traffic control computer screens to go dark for roughly 60 to 90 seconds and also prevented the controllers from talking to aircraft during the outage, multiple sources with knowledge of the incident told ABC News. As a result, the FAA halted all departures to the Newark airport, citing “telecommunications and equipment issues at Philadelphia TRACON.”

Following the April outage, several controllers went on medical leave, calling the experience a traumatic event. The controllers are entitled to at least 45 days away from the job and must be evaluated by a doctor before they can return to work.

ABC News’ Sam Sweeney and Ayesha Ali contributed to this report.