A bumbling TSA officer created a security headache at Newark Airport last weekend after he mistakenly assumed a civilian was in a group of federal sky marshals and let him past a checkpoint, police sources said yesterday.

Hundreds of travelers were inconvenienced for 90 minutes and several departing flights were delayed as Port Authority cops and the FBI scrambled to learn whether the interloper posed a terror risk, the sources said.

The civilian, who was trying to greet his wife at about 4:30 p.m. Saturday, innocently thought he could follow the others through security.