BEIJING -- Chinese authorities on Wednesday issued an orange alert, the second highest-level warning, for forest fires in parts of China from May 1 to 5.

The national forest and grassland fire-control command office and the Ministry of Emergency Management (MEM) issued the alert for forest fires in parts of Hebei, Shanxi, Henan and Shaanxi during the five-day May Day holiday.

The emergency management departments have been instructed to closely monitor changes in fire hazards, implement early warning and response measures, continuously reinforce fire source control, strengthen emergency preparedness, and effectively address the ongoing severe risk of forest fires.

Forest and grassland fires are among eight major natural disasters. "Generally speaking, China's forest fires have shown an overall downward trend in recent years," said Yang Xudong, an official with the MEM, on March 21, the International Day of Forests.

Statistics show that, from 1950 to 1989, China averaged approximately 16,000 forest fire incidents annually. This number dropped to around 6,000 between 1990 and 2020, and since 2021, it has further decreased to less than 1,000 cases per year.

The causes of forest and grassland fires are categorized into natural and human factors, with the latter accounting for over 90 percent of the causes of fire incidents, according to Yang.

China has a four-level warning system for forest fires, with red being the highest followed by orange, yellow and blue.