Federal authorities are investigating a flurry of incidents in which Delta jets were hit by lasers near Los Angeles International Airport Sunday.
The Federal Aviation Administration said it is not unusual to see clusters of laser strike reports like those in major metropolitan areas.
However pilots have said such behavior can injure flight crews, and could cause deadly accidents.
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"Lasers, they can be dangerous. (They) are not a toy. They can actually cause retinal damage, a lesion on the retina," commercial pilot Mark Galsihoff, who flies out of LAX for a major commercial airline, said.
And NBC4 helicopter pilot Alex Kriewall also condemned such attacks, which are becoming ever more common.
"When we are out there with multiple helicopters all in the same proximity if you lose visual reference that can be a very dangerous scenario," Kriewall said.
On Sunday DAL1211, a Boeing 767, reported a laser strike inbound at 2,500 feet while westbound seven miles east of LAX around 4:45 p.m. At the exact same time DAL34, a Boeing 767, reported a laser strike outbound at 14,000 feet while northeast bound about 12 miles northeast of LAX.
And DAL984, a Boeing 737, reported a laser strike inbound while heading west at 6,000 feet approximately 25 miles east of LAX around 10:30 p.m.
That same night a first officer had to be cleared by a doctor in Oregon after jetting from LAX to Medford. He was targeted by a laser while preparing to land.
It is unclear at the moment if any of the incidents are related.
The numbers of such incidents have jumped significantly, with pilots reporting 100 laser strikes around Los Angeles in 2014 through December 11.
Nationwide, the Federal Aviation Administration reported the number of lasers being pointed at aircraft jumped from 384 in 2006 to 3,960 in 2013, an average of 11 per day.
Michael Larkin also contributed to this report