Authorities discovered a suspicious powdery substance at La Guardia Airport on Friday, leading to the partial evacuation of the main terminal and treatment of 10 people who said they felt ill.
The substance was discovered about 1 p.m. during the search of a handbag at an American Airlines section of the terminal, said a police spokesman for the Port Authority of New York and New Jersey, which operates New York City's airports.
Results of an on-site test were inconclusive, and a hazardous materials team was called to the scene to investigate, police said.
The 10 people were treated at the scene "as a precautionary measure," said Frank McCartney, a spokesman for the Office of Emergency Management.
Their symptoms were considered minor, he said.
The terminal was partially evacuated until officials determined that there was no further threat, police said.