US investigators are examining a spate of cases in which laser beams have been shone into the cockpits of aircraft.
It is against federal regulations to shine a laser at an aircraft
The most recent case was in Cleveland, Ohio, on Monday night, where a pilot says a green laser light was shone through the window of his cockpit.
The light tracked with the plane for several seconds as it came in to land.
The FBI, worried that terrorists may use lasers to stun and disorientate pilots, is investigating a series of similar incidents involving lasers.
The FBI has recently warned law enforcement agencies that terrorist have explored using lasers as weapons. However, authorities say they have no specific intelligence to link the incidents with al-Qaeda activities in the US.
"It didn't just splash and vanish, which made the pilot believe he was being tracked," FBI agent Robert Hawk told AFP news agency.
The pilot landed the plane and the FBI traced the beam to a residential area of Cleveland.
Six similar incidents are being examined by the FBI.
On Monday, two pilots in Colorado reported green pulsating laser beams in their cockpits in Colorado Springs. Both planes landed without incident.