Firefighters walk to put out forest fire at Yunlang Village of Fengyi Town in Dali Bai Autonomous Prefecture, southwest China's Yunnan Province, May 22, 2018. A forest fire that broke out on May 22 at Yunlang was completely extinguished as of Wednesday morning. (Xinhua/Yang Yingwu)

KUNMING, May 23 (Xinhua) -- A forest fire in southwest China's Yunnan Province was extinguished early Wednesday morning after burning about 40 hectares, local authorities said.

The fire started in Yunlang village, Dali City at around 11 a.m. Tuesday. About 1,500 people from the local armed police, forest police, militia and firefighting forces, as well as three helicopters, were sent to the scene.

The blaze followed another fire that broke out on May 19 in Wanqiao village, also in Dali. The fire, which was put out the next day, burned about 10 hectares of forest.

An investigation into the cause of the fire is under way.