New scare on Northwest Airlines flight

A confrontation with a passenger sparked another security scare Sunday at Detroit's Metro Airport involving the same Northwest Airlines flight that was the target of an in-flight bombing attempt two days earlier, officials said.

The flight crew became concerned after the man, identified as a Nigerian, became sick and spent about an hour locked in the bathroom. When he came out, he became verbally abusive, CNN reported.

The U.S. Transportation Security Administration said the airline alerted authorities to a "disruptive passenger" aboard flight 253 from Amsterdam and the pilot requested emergency assistance upon arrival.

The Federal Aviation Administration said the plane landed "without incident" around 12:35 p.m. ET and it was removed to a remote area. A man was taken into custody and passengers' suitcases were lined up on the ground for inspection.

Two law enforcement officials said post-flight interviews by investigators determined the passenger was a legitimate businessman who posed no security threat to the plane.

"The investigation shows that this was a non-serious incident and all is clear at this point," FBI spokeswoman Sandra Berchtold said.

On Christmas Day, a Nigerian man was charged with trying to destroy an aircraft after passengers and crew quickly moved to extinguish a fire that was allegedly sparked by an explosive device.

Operated by Delta

All 256 passengers on Sunday's flight were taken by bus to the airport terminal for questioning, according to a spokeswoman for Delta Air Lines, which operates Northwest.

Emergency vehicles surrounded the plane as it remained parked about a kilometre from the main airport buildings for more than three hours.

There is no indication so far that Friday's foiled attack, which ended with the arrest of Umar Farouk Abdulmutallab, 23, is linked to a larger international plot. The suspect's possible ties to al-Qaeda are still under investigation.

Abdulmutallab is alleged to have carried the explosive in condom-like pouches attached to his body. The fire and struggle to subdue the suspect occurred about 20 minutes before the plane landed.

A day after the incident, new security flight rules were introduced. Passengers with U.S. destinations are now barred from leaving their seats for the last hour of their flights.

They also face additional security checks that have caused long delays at several airports.