(Yonhap) -- Dozens of villagers evacuated to a temporary shelter Saturday as officials tried to assess the extent of damage from a poisonous gas leak that devastated a large farmland.

   About 70 elderly residents left their village, Bongsan-ri, in the southeastern city of Gumi to a public facility considered safer from the aftermath of the Sept. 27 leak of about eight tons of hydrofluoric acid.

   The chemical is an acute poison which can damage lungs and bones and affect the nervous system.

   The village is home to about 300 people, and the disaster management office in Gumi said the rest will be evacuated in stages. The evacuation came after villagers demanded their relocation in a meeting earlier in the day.

   "We decided to relocate by ourselves as the government is doing nothing for us," village leader Park Myung-seok said, demanding the Gumi city government and the Bongsan-ri office provide them with shelters.

   Residents in nearby Imcheon-ri village are also demanding evacuation, officials said.

   Five workers were killed in the accident at the compound of chemical maker Hube Global at the Gumi National Industrial Complex in the industrial city, about 200 kilometers southeast of Seoul.

   The secondary damage has been extensive and fast spreading.

   A total of 1,594 people have been treated for nausea, rashes and other symptoms. Crops and fruit on more than 90 hectares of farmlands and orchards have withered, and some 1,300 livestock animals have been drooling heavily or showing symptoms similar to a human cold.

   On Saturday, the disaster management office in Gumi said 73 companies have reported they have suffered property damage worth a combined total of about 9.4 billion won (US$8.5 million) from the accident.

   The region could be designated as a special disaster zone, which allows for financial assistance from the central government to cover rehabilitation costs, as well as tax cuts and other benefits for residents, officials said.

   The government has been under fire for responding poorly to the accident.

   Firefighters failed to use calcium hydroxide, the neutralizing agent for hydrofluoride, in the first place and the local authorities were slow to evacuate workers at the factory and residents in nearby regions.

   The government has pledged comprehensive measures to support victims and prevent further damage. On Friday, a team of 26 investigators and concerned officials led by the Prime Minister's Office launched an investigation to assess the extent of the damage.