Four people were killed and about 70 others injured after a fire set as part of a traditional South Korean festival spread out of control, police said Tuesday.

The accident happened when organizers set fire to reed-like plants at the top of Hwawang mountain in southeastern South Korea on Monday night as part of the full moon festival, said Park Joong-soo, an officer at Gyeongnam Provincial Police Agency.

The blaze, fanned by sudden winds, spread over firebreaks, forcing spectators to flee. Four of them, who were on top of a large rock to get a better view of the festival, fell about 10 yards to their deaths while trying to dodge the fire, according to Park.

He said the fire left about 70 others injured, with four or five suffering serious burns.

Park said there were about 15,000 spectators at the scene.

It is a South Korean tradition to set fire to grass along rice fields on the night of the first full moon of the Lunar New Year in the belief that it helps bring good harvests and drives out evil spirits, though it is no longer widely practiced.

This year's first full moon on the lunar calendar fell on Monday. South Koreans celebrated the start of the Lunar New Year on Jan. 26.

The county government in Changnyeong, about 162 miles southeast of Seoul, has organized the fire festival about once every two years since 1995.