It was abnormally foggy yesterday in many areas of Vietnam, causing many flights to be canceled for safety reasons. Some people inferred that the poor visibility might have been caused by last week’s forest fires in Indonesia.

Nguyen Van Tam, deputy director of the Ba Ria-Vung Tau province Hydro-meteorological Center, said that the poor visibility was not caused by fog, but by smoke. Such an air pattern, which was also recorded on Con Dao Island, reduced visibility by 2-5 km, Tam said.  “It might be caused by smoke from the forest fire that occurred on Indonesia’s Sumatra Island last week,” Tam said. In 2007, when a volcano erupted in Indonesia, Vung Tau also suffered from dust and smoke, he added. Due to the poor visibility, authorities canceled eight flights of helicopters to offshore oil drilling rigs yesterday. Similar condition were recorded in other provinces, such as Khanh Hoa in Central Vietnam, and Can Tho, Hau Giang, and Ca Mau in the south. The bad weather delayed two flights from Ho Chi Minh City to Con Dao and Ca Mau, and the cancellation of another flight from Can Tho to Con Dao, said Pham Thanh Tam, director of the Can Tho International Airport. Meanwhile, Nguyen Minh Giam, head of the Southern Hydro-meteorological Forecasting Station, said the thick fog was caused by the tropical storm Bebinca, which hit several northern provinces a few days ago. The storm caused heavy rain, after which water evaporated into the air and formed fog, Giam explained, stressing that such fog was not from the forest fire in Indonesia. Meanwhile, dust and smoke from the forest fire continued to affect most of Malaysia, causing extremely serious pollution in its southern areas. In Kuala Lumpur, the pollution index has reached 200, an “extremely harmful level to health”, and authorities have ordered all schools closed.