The government of Canada is issuing a sweeping ban on the possession of some handheld lasers near airports in an effort to prevent cockpit attacks.

Transport Minister Marc Garneau took the unusual step today of announcing an interim ministerial order that bans the possession outside of a private dwelling of battery-operated, handheld lasers more powerful than one milliwatt anywhere within 10 kilometres of an airport or heliport, and in any municipality within the greater Toronto, Montreal and Vancouver areas.

The order exempts those with legitimate reasons for using a laser pointer outdoors, citing "work, school or educational purposes."

Any individual caught violating the ban could face a fine of up to $5,000, while corporations could be on the hook for $25,000.

A laser pointed into the cockpit of an aircraft can distract and even momentarily blind a pilot.

"This creates a very disturbing effect inside the plane. It can cause flash blindness," said Garneau.

Since Garneau initiated a public education campaign on such cockpit attacks two years ago, the number of laser incidents has dropped by 25 per cent.

There were 379 reported incidents of lasers aimed at planes last year, down from 590 in 2015 and 527 in 2016.

"It's still too many. We want it to be zero," said Garneau. "The education is working, but it's not working fast enough."

Shining a laser into a plane's cockpit is already a federal offence under the Aeronautics Act, but the government has said it's difficult to prosecute.

The new measure gives police the power to question anyone found in one of the prohibited zones with a laser.

"Like any other infraction, they would need a reasonable reason to search someone (ie. someone reports seeing a specific person in a park with a red hoodie, grey jeans, blue shoes, holding a laser)," said Garneau's press secretary Delphine Denis in an email.

"If you are sitting on a bench with a 1 mw (or more) laser in your hand and police see you, you will need a legitimate reason to have it in your possession or else they can fine you on the spot."