Fox News is reporting an airline mechanic, who allegedly sabotaged a Nassau-bound Boeing 737 in July over what he says was disappointment related to a labor dispute, was denied bail Wednesday due to the judge’s concerns about the mechanic’s potential ties to ISIS.

Abdul-Majeed Marouf Ahmed Alani, a naturalized American citizen originally hailing from Iraq, was ordered held in Miami during a hearing for charges he glued styrofoam to an airplane’s part that helps track critical flight data such as airspeed. The plane, which contained 150 passengers, was grounded and ultimately taken off the tarmac where the problem was discovered. He is charged with “willfully damaging, destroying or disabling an aircraft.”

U.S. Magistrate Judge Chris McAliley denied bail to Alani when presented evidence by prosecutors that Alani’s brother may have ties to ISIS and had a history of incriminating statements wishing harm on non-Muslims.

Evidence was also presented that Alani had sent $700 to someone in Iraq recently, had in fact traveled to his home country without disclosing that information during his arrest, and had videos on his phone of ISIS militants engaged in murder.

“You may be very sympathetic to terrorists,” the judge told Alani at the hearing. “That’s very disconcerting.”

Alani, 60, worked as a mechanic for the airline when he allegedly sabotaged a Nassau-bound Boeing 737 with 150 passengers and crew aboard at Miami International Airport over stalled labor negotiations. He allegedly told investigators the labor dispute between the mechanics union and the airline had a negative financial impact on him. Prosecutors said Alani glued styrofoam inside the nose of the aircraft that disabled a part used to gauge airspeed and other critical flight data. Pilots detected the issue before takeoff, and the plane was taken to another part of the airport for an inspection. That’s when the problem was discovered. Airport surveillance captured Alani working on the plane’s nose. He was identified by co-workers.

Alani, who the judge believes is a flight risk, will be held without bail and will enter a plea Friday.