SAN JOSE, Philippines, Friday (Reuters) Philippine health authorities finalised test results on Friday that could show the cause of food poisoning that killed 26 children, as grieving villagers prepared to bury more bodies. Doctors from the health department's national epidemiology centre said results of initial laboratory tests on blood and vomit samples from the victims who ate the poisoned cassava snacks may be known on Friday.

"We hope we can come up today with definite answers," Troy Gepte, head of a team of doctors investigating the food poisoning on Bohol island in the central Philippines.

"We have some tests results, but we have to come up with a consolidation of our findings, assessment of doctors who treated the children and accounts of what happened in the area."

He said there were two possible causes of poisoning - a high level of the cyanide that can naturally form in the root vegetable, or pesticide contamination.

Most of the children treated in hospitals showed symptoms of cyanide or pesticide poisoning, he added. Villagers buried on Thursday 12 of the 26 children at a public cemetery, including two grandchildren of one of the two women who cooked and sold cassava fritters to the children.