BANGKOK, Thailand -- Revelers in northern Thailand have been asked not to launch lanterns into the sky near airports to avoid airborne accidents during a popular festival later this week, airport officials said Tuesday.

The air traffic control centre in the province of Chiang Mai has declared a 5-kilometre restricted zone around the airport where lanterns are banned from Wednesday to Friday, during the festival takes place, the centre's director Kiattisak Rienvatana said.

During the festival known as Loy Krathong, Thais float small rafts into rivers to ask for forgiveness from the goddess of water.

Residents in northern Thailand also believe that flying the floating lanterns also will rid them of bad fortune, but it has posed aviation risks in recent years.

"We are asking the people to co-operate because only one lantern can bring down a plane," Kiattisak told The Associated Press by telephone. "Our officials are also keeping an eye on any lanterns that might be blown into the airport parameters during that period."

Revelers are advised to float the lanterns after 9 p.m. when the air traffic is cleared up.

Several airlines, including Thai Airways, have adjusted their flight schedules to give way to the lantern floating, which takes place mainly after dark.