Four children and a woman died immediately, while another girl child succumbed to injuries in the hospital, they said.The three boys and two girls, all LKG and UKG students, were on their way to school in Pettah in the city, they said.

Police said the vehicle hit a block of stone and plunged in to the canal as there was no protective barrier along the narrow road.The van, half-submerged in the polluted canal, was first noticed by the crew of a bus that passed by the spot.

They immediately informed the police, who with the help of local people, began the rescue work.Three children and the van driver are undergoing treatment at a hospital and their condition is stated to be stable.

Home Minister Kodiyeri Balakrishnan directed IGP B Sandhya to probe the incident and submit a report.According to the locals, the van carried nine children besides the woman attender and the driver, they said.

Education Minister M A Baby, who rushed to the spot, said an inquiry would be ordered into the safety aspects of school vehicles.