New York ? The Delta Airlines terminal at La Guardia Airport was evacuated for about 90 minutes Friday because of a security breach, inconveniencing hundreds of travelers, authorities said.

Aircraft that had left the terminal and taxied out to runways were ordered back to the terminal, said Federal Aviation Administration spokesman Jim Peters. He said the evacuation began at about 10 a.m.

An official for an airline, speaking on condition of anonymity, said a passenger on a stretcher had passed through a security checkpoint, but two medical workers accompanying the patient were not screened. When authorities learned of this, the official said, they ordered the terminal evacuated.

The terminal was reopened at about 11:30 a.m.

A spokesman for the Port Authority of New York and New Jersey, which operates the airport, referred questions to the FAA.

In addition to Delta flights, the terminal also services Northwest Airline passengers.

A Delta spokeswoman said 13 flights, including seven commuter flights, and about 1,400 passengers were affected by the evacuation. Two Northwest flights, involving about 300 passengers were also affected, a spokesman said.