Someone pointed a hand-held laser at the cockpits of two planes landing at the Calgary airport recently, causing serious safety concerns, Transport Canada says.

Similar incidents have happened in Calgary six times in the past 24 months.

In late February, the crew of an American-owned passenger jet reported seeing a flash of green light while approaching the runway, Transport Canada spokeswoman Jacqueline Petrus told CBC News.

Thirteen minutes later, a similar report came from a second plane during landing, she said.

Both reports suggested the flash originated from a suburban area in the northwest area of the city.

Although the planes landed safely, she said such flashes of flash of light could distract or temporarily blind pilots when they needed to concentrate on the ground below.

This is the sixth laser report from the Calgary airport in the past two years, she said.

Transport Canada said on Thursday that 33 such complaints have been made across the country since 2005.

"Transport Canada, specifically, is very concerned about the increasing frequency of laser-related incidents, whether they're directed at any transportation mode —aircraft, cars, trucks, boats or trains," Petrus said.

Although most consumer laser pointers are not powerful enough to cause a problem, those with military, medical or research applications can reach altitudes capable of affecting pilots, she said.

Transport Canada has asked the police to investigate.