The FBI is looking at seven incidents of laser beams being aimed at the cockpits of airplanes in the past week, which officials fear could temporarily blind a pilot and cause a crash.

Stray beams from commonly available laser-generating devices occasionally find their way into the cockpit of a plane approaching a runway for landing, but a rash of incidents since Christmas have the FBI looking at whether there is an organized effort to bring down a plane.

Two incidents have been reported in Colorado Springs, Colo., as well as one each in Cleveland; Washington; Houston; Teterboro, N.J.; and Medford, Ore.

All of the planes landed safely.

Federal officials say there is no evidence of organized activity, but the FBI warned earlier this month of the possibility that terrorists might try to use lasers as weapons.

Pilots are also concerned, given that a laser could temporarily blind and disorient them.

"It's not some kid," Paul Rancatore, a pilot who serves as deputy chair of the security committee for the Allied Pilots Association, told the Associated Press news agency. "It's too organized."

An expert in military technology at Georgetown University told AP that a laser powerful enough to cause an airplane to crash would be expensive and sophisticated.

"What we're talking about is a fairly powerful visible light laser that has the ability to lock onto a fast-moving aircraft," said Loren Thompson. "That's not the sort of thing you pick up at a military surplus store."

But law enforcement officials say they are talking about devices that are readily available – such as classroom pointing devices, for example.

A memo recently sent by the FBI and the Homeland Security Department, however, warns law enforcement agencies of evidence that terrorists have explored using lasers as weapons, but not necessarily in the United States.

In the past decade, hundreds of cases of lasers shining into pilots' eyes have been reported. Pilots sustained damage to their eyes in several of those incidents.

Outdoor laser light shows have also caused temporary eye injuries to several pilots over the last decade, spurring aviation authorities to create strict rules about their use in the vicinity of airports.