A heavy police presence temporarily restored peace to turbulent Fengxiang county in Shaanxi province yesterday, where hundreds of villagers stormed a chemical plant that is being blamed for more than 600 children falling ill. The Fengxiang government deployed thousands of police and plain-clothes officers outside the Dongling Lead and Zinc Smelting plant yesterday to prevent further unrest. More police and their vehicles could be seen patrolling streets in nearby villages. On Monday furious residents tried to storm the smelting factory, tearing down the fence and throwing rocks at trucks. There were no fresh protests yesterday but the situation remained tense, with anger simmering among the parents of lead-poisoned children. Despite the authorities' warning, residents continued yesterday to block the main road leading to the plant from Baoji city. They said they would fight until the government drew up plans for a clean-up. Signs of violence could be seen everywhere in the factory, with brick walls torn down and the windows of the factory's reception area and security office smashed. 'There are too many police today and protesters are simply not able to get close to the factory,' said the owner of a convenience shop near the plant. A Sunjianantou villager who took part in Monday's protest said residents enraged by official cover-up of the pollution for at least three years were not afraid. 'We will take to the streets again to attract more outside attention to our suffering,' he said. The villagers demanded authorities provide free checks to all who live near the plant. Only 731 children in the two villages under the age of 14 have been given free check-ups and 615 of them have tested positive for lead poisoning so far, which can harm the nervous and reproductive systems and cause brain damage. Villagers at one of the potential sites for resettlement said their children also suffered from lead poisoning. Wang Liming , a 27-year-old Madaokou villager, said: 'I don't understand why we should move to make way for the polluting factory. And why should we bother to relocate to a polluted site?'