By Greg Argos

PHILADELPHIA (CBS) — Philadelphia International Airport is operating under a heightened alert after the attacks in Brussels. American Airlines has announced that they have cancelled their only direct flight into Philadelphia from Brussels.

Airport officials are telling passengers to expect to see extra security, a direct response to the terrorists attacks that rocked Belgium’s capital city.

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Some passengers admitted that they are on edge and paying extra close attention to their surroundings. “I think that a lot of airports try to make sure we all feel safe and secure,” said Amanda Burke.

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“I feel pretty safe coming to the airport, but I know it can be scary with everything going on internationally,” she added.

Businessman John Wiley arrived at Philadelphia International Airport on a direct flight from Paris and he heard the news of the attacks moments before boarding that flight. “By the time I boarded the plane, we had just gotten the news that people actually died,” Wiley said.

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Wiley said this latest attack will only increase his awareness when traveling. “Living in Center City Philly, having grown up in New York, you learn to pay attention. I’m not really one to walk around with blinders on. I mean, I was flying on 9/11. It hasn’t been the same since.”