Two children have died from a wave of mysterious poisonings over the last two days in Angolan schools, but police have yet to identify the toxin that has sown panic in the country, officials said Friday. About 300 students from both public and private schools have been hit by symptoms that include vomiting, headaches, sore throats and sometimes suffocation, said Renato Paulo, director of the hospital in Luanda's Cacuaco district. Two children have died of the poisoning, he added. Across Angola, nearly 570 cases have been recorded. National police chief Elisabeth Rank Frank said on national radio that the poisonings were being taken extremely seriously. "The police are aware of the situation. So far, they have no explanation for the phenomenon. We should take the time needed to conduct an investigation," she said. "We are working with the ministry of health on several samples take from the field to throw some light on this affair. And we are working with the ministry of education to reinforce security at Luanda schools," she added. Luanda governor Jose Maria dos Santos urged the public to remain alert for anyone attempting to cause further harm at schools.