MAE HONG SON, Thailand - Flights to the border town of Mae Hong Son in northwestern Thailand were canceled Thursday because of poor visibility caused by thick smoke from brush fires, an airline official said.

Thai Airways International said it canceled all three flights from the northern city of Chiang Mai to Mae Hong Son, 400 miles northwest of Bangkok.

"The visibility is way below the standard for flying," said Sayamol Khajadpai, a public relation officer for the airline. "We may have to cancel Friday's flights as well if it is not getting better."

Brush fires this year have already burned more than 1,580 acres in seven districts of the province. The forestry department's firefighter units are still battling to put out the fires, but insist they have the situation under control, said Mae Hong Son Governor Poj U-thana.

The governor blamed the fires on villagers who try to clear land by burning the growth on it. He said the practice continued despite publicity campaigns against it and the threat of jail terms.