OKLAHOMA CITY - Oklahoma City police officers are sounding the alarm on a dangerous prank that can cause planes and helicopters to crash.

The city's finest eyes in the sky are under attack by thin rays of light, and it's happening more and more.

News 9 first reported the recent dangers of laser lights and aircrafts on Monday. Now, police are experiencing a rise in cases where laser lights are being pointed at aircraft.

In just the past six days, Oklahoma City police have investigated four incidents. A laser light hit a medical helicopter and a police helicopter on Thursday. On Sunday and Monday, a police chopper was the target again.

"It's kind of rare that we would have this many all at one time," MSgt. Tod Yates of OCPD's air support unit said.

Pilots say when a laser hits an aircraft, it causes a major distraction. Yates has been hit by a laser while in the air.

"It's temporarily blinding you," Yates said. "Your eyes will water … you'll have kind of a headache sensation."

On Thursday, a medical helicopter was transporting a patient to Baptist Medical Center when it was hit by a laser. A police chopper went in to investigate and was also hit. That all happened over northwest Oklahoma City.

On Sunday and Monday, police were hit again over at S.W. 89th Street and Santa Fe in Oklahoma City.

"We have several tools at our disposal on board the aircraft that allows us to more accurately locate [suspects]," Yates said.

A total of three suspects were identified and may face federal charges.

"If it causes enough damage to the eye, the pilot can lose his medical, which in turn, he can lose his job," SkyNews 9 HD pilot James Albertson said. "That's why I think the federal government is taking it so serious."

Police believe the rise in the crime is most likely because of the increased availability of laser lights.

In May, the cockpit of a Delta Airlines flight was hit while on approach at Will Rogers World Airport. Police say that is extremely dangerous because the aircraft was so close to the ground at that point.