Aviation security officials will begin enhanced screening measures of passengers' electronics at US airports, the Transportation Security Administration announced Wednesday.

Travelers must remove electronics larger than a mobile phone from their carry-on bags and "place them in a bin with nothing on top or below, similar to how laptops have been screened for years. This simple step helps TSA officers obtain a clearer X-ray image," the TSA announced amid growing fears that electronic devices can pose as homemade bombs.

"Whether you’re flying to, from, or within the United States, TSA is committed to raising the baseline for aviation security by strengthening the overall security of our commercial aviation network to keep flying as a safe option for everyone," TSA Acting Administrator Huban A. Gowadia said. "It is critical for TSA to constantly enhance and adjust security screening procedures to stay ahead of evolving threats and keep passengers safe. By separating personal electronic items such as laptops, tablets, e-readers and handheld game consoles for screening, TSA officers can more closely focus on resolving alarms and stopping terror threats."

Some passengers are exempt

But the new rules don't apply to everybody. The TSA was quick to point out that the revised security measures do not apply to passengers enrolled in the TSA Precheck program.

The development comes amid the heightened scrutiny of electronics coming into the US on international flights, largely on Middle Eastern airlines. In March, US aviation security officials barred electronics larger than cellphones in carry-on bags of direct flights to the US from nine airlines at 10 airports overseas.

Moreover, the new domestic screening methods come days after the US Government Accountability Office said in a new report that the TSA "does not have valid evidence" supporting the bulk of its methods to identify behavioral threats to aviation security.

The GAO report is in line with an American Civil Liberties Union study, based on a Freedom of Information Act request and released in February, that showed little scientific support for the TSA's protocol to weed out terrorists based on their behavior at airports.

Last year, taxpayers spent about $186 million to deploy 2,393 officers to blend in at 87 airports to help with screening and identify possible terrorists. The GAO report said there was little science behind how it singled out criminals.

"TSA does not have valid evidence that most of its indicators in its revised list of behavioral indicators can be used to identify individuals who may pose a threat to aviation security," according to the GAO report. Of the TSA's 36 behavioral indicators to identify threats, just eight of them were supported by science, the report said. The report said that of the 178 sources TSA used to justify its program, only three were deemed valid by the GAO.

Meanwhile, the TSA said that the new electronics screening measures are already in place at 10 airports and that the program is expected to roll out nationwide in the coming weeks and months.