NEW YORK (CBSNewYork) -- Three Transportation Security Administration workers were hurt after being exposed to a unknown substance in what was described as a hazardous material incident at LaGuardia Airport.

It happened just before 6 a.m. Wednesday at Terminal B.

The TSA said agents found an unknown substance in a carry-on bag after an alarm went off at a checkpoint area. The workers were complaining of eye irritation after being exposed to what the Port Authority said was a "food substance."

Port Authority police were notified "out of an abundance of caution," the TSA said. The checkpoint was closed for about a half hour, but it has since reopened.

No passengers were hurt.