Health authorities in Senegal are looking into the unexplained deaths of about 20 small children in a poor suburb of Dakar, a regional medical chief said Friday.

"Investigations have begun to find out many (children) and what happened," Khemes Ngom told AFP, confirming press reports that 18 to 20 children, aged three to five, died in the fishing district of Thiaroye-sur-Mer.

"People reported symptoms such as convulsions, vomiting and diarrhoea," she said, "but after tests, paediatricians and doctor have ruled out diseases such as cerebral malaria, typhoid fever, meningitis and cholera."

Ngom said that samples -- including ones from car batteries -- had been gathered in Thiaroye-sur-Mer to be sent to health ministry laboratories.

The private weekly L'Observateur reported that the children might have been poisoned by lead from car batteries left on a public waste tip, because "people living in poverty fetch them to resell them."