A suspicious man has tried to get into restricted areas and aircraft at airports across the country, most recently in Maryland, federal authorities said.

In a be-on-the-lookout notice issued by the Transportation Security Administration, authorities identified the man as Ahmed Olasunkahmi Salau, who also goes by Salan, Saluh and Martinez Davon Wells.

The TSA said Salau has posed as either a passenger, employee or crewmember with the intent to get onto aircraft or into facilities. The TSA said Salau has a working knowledge of airport operations and initially sounds credible.

According to the TSA, Salau's verified airport encounters date back to October 2016.

In October 2016, Salau traveled on a commercial airline under a false name using a fraudulent photo ID.

In the Maryland region, the TSA said Salau made several attempts this year to get onto aircraft at Washington Dulles and Reagan National airports. At Tipton Airport in Fort Meade and at Frederick Municipal Airport, Salau is said to have pretended to be a pilot. And the TSA said he tried to gain access at the College Park Airport to board a charter flight.

  • October 2016: Houston: George Bush Intercontinental Airport
  • February 2017: Columbia, Missouri, Regional Airport
  • Week of April 17, 2017: Macon, Missouri
  • April 19, 2017: Jefferson City, Missouri: Jeff City Flying Service
  • April 24, 2017: St. Louis: St. Louis Lambert International Airport
  • April 27, 2017: Chicago: O'Hare International Airport
  • May 9, 2017: Chicago: Midway International Airport
  • May 27, 2017: Farmingdale, New York: Republic Airport
  • July 2 and 5, 2017: Washington Dulles International Airport
  • July 8 and 11, 2017: Washington Reagan National Airport
  • Sept. 22, 2017: Fort Meade, Maryland: Tipton Airport
  • Sept. 29, 2017: Leesburg, Virginia: Pro Jet Aviation
  • Sept. 29 and 30, 2017: Frederick, Maryland: Frederick Municipal Airport
  • Oct. 2, 2017: College Park, Maryland: College Park Airport

According to Maryland aviation authorities, Salau has also visited Martin State Airport in Baltimore County on three separate occasions, which included a stop at Middle River Aviation.

"So when he came in, I thought he was just a regular customer, and that's what I treated him like. He asked questions about flight training and I answered his questions," said Alysse Gapsis, a Middle River Aviation employee.

But when he didn't leave the area, airport officials were notified.

"But these things can't be prevented totally. We all have to play our role in wanting to keep everybody safe and following procedures," Gapsis said.

The TSA said Salau may have also called facilities in an attempt to get passenger and aircraft data.

The TSA said it issued the notice for security awareness.

As the TSA and airport security keep watch for Salau, Baltimore County police arrested another man, Jesse Davis, 30, of Pikesville, on Thursday on a trespassing charge. He was found for the second time in a secured area of Martin State Airport. Last week, airport officials had banned Davis from the property