NBA fans flying to Boston to see Tuesday’s Sixers-Celtics game were delayed at Philadelphia International Airport by a perceived bomb threat on a passenger’s cellphone, authorities said.

American Airlines Flight 1677 had been scheduled to take off at 12:54 p.m., but initially was delayed by a mechanical problem. Around 2:11 p.m., flight attendants alerted the plane’s captain that a male passenger was “displaying suspicious material on his cellphone, possibly alluding to a bomb threat,” according to Sgt. Eric Gripp, a spokesperson for the Philadelphia Police Department.

Gripp did not specify what was seen on the phone, but said the message was "the passenger’s WiFi sign-on address.”

K-9 units and airport police responded, and the passenger eventually was cleared by an investigation, police said.

The nearly full flight had been scheduled to arrive in Boston at 2:10 p.m. but did not arrive until 4:41 p.m., American Airlines spokesperson Ross Feinstein said. The NBA game at Boston Garden started at 5:30 p.m.

The threat was “noncredible,” Feinstein said. “The issue was quickly resolved, and the flight departed.”

ESPN reporter John Barr tweeted that he was on the flight with his 15-year-old son who was wearing a Joel Embiid jersey and Sixers hat and “wanted nothing but this for Christmas.” Barr tweeted that the passenger whose phone caused the delay “should get nothing but coal in their stocking.”

“Actually, I wish that person would identify themselves now because I have about a dozen angry Sixers fans who would like to have a word,” Barr tweeted.