The 737 MAX airplanes have recently been grounded worldwide following another crash in Ethiopia earlier this month, which killed all the 157 people aboard. In an international notice published Wednesday, the Federal Aviation Administration (FAA) said investigations surrounding the two accidents "developed new information indicating some similarities" between them.

The FAA said it "is aware that Boeing is developing a Service Bulletin that would specify the installation of new flight control computer operational program software," adding that the company has also developed "flightcrew training related to this software."  

"The FAA's ongoing review of this software installation and training is an agency priority, as will be the roll-out of any software, training, or other measures to operators of the 737 MAX," according to the agency.

In last week's notice, the FAA said Boeing is developing flight control system changes to address the Lion Air accident, which killed all 189 passengers and crew in October.

Investigators are looking into whether faulty data coming into the Maneuvering Characteristics Augmentation System drove the Indonesian airline's flight into a steep dive that the pilots were unable to overcome. On Wednesday, the FAA said it will continue to analyze any information discovered during the investigation of the crash of the Ethiopian Airlines Flight 302.

The cockpit voice recorder and flight data recorder information have been downloaded from the units and are now in possession of the Ethiopian authorities, it added. Elaine Chao, the U.S. transportation secretary, sent a memo to the department's inspector general on Tuesday, formalizing a request for an audit of the FAA's certification of 737 MAX. The U.S. Federal Bureau of Investigation (FBI) is reportedly assisting a criminal investigation into how Boeing's 737 MAX was certified to fly.