(Adds toll from railway company, number of injured) JAKARTA, Nov 20 (Reuters) - The last carriage of an Indonesian train plunged into a river on the island of Sumatra on Monday, killing at least eight people and injuring nearly 40, hospital officials and the Antara news agency said. The accident happened 6 km (3.7 miles) outside the town of Lubuk Linggau in South Sumatra province after the train passed a small bridge, Antara reported. Erlansi, the head of the railway company in South Sumatra, was quoted by Antara as saying two coaches derailed and one of them fell into the river, killing nine people. Hospital officials told Reuters eight people had died and 38 were injured. Indonesia has a relatively poor record of transport safety, with much of the infrastructure in the sprawling Southeast Asian country ageing and overstretched.