A forest fire in northeast China's Heilongjiang Province was extinguished early Friday morning after an all-day effort by 5,000 firefighters, local authorities said Friday.

Firefighters work to control a forest fire in Jiayin County of Yichun, northeast China's Heilongjiang Province, May 5, 2011. Suddenly occuring here on Thursday morning, a forest fire has been broken under control as of the press time. [Xinhua]?

The fire, which occurred in Jiayin County in the city of Yichun, was put out by the firefighters despite obstacles such as the area's strong winds, said an official with the city's forest fire control headquarters.

The firefighters are still keeping a close eye on the burned area to rule out any possible fire hazards, he said.

The fire, which stretched about 500 meters into the forest, ignited Thursday morning.

Police are still investigating the cause of the fire.