At least 10 Sri Lankan civilians were killed and dozens more wounded Sunday when artillery shells fell inside a government-designated "safe zone" in the heart of Tamil Tiger rebel territory, a health official said. Government forces have driven the rebels from most of their strongholds in recent months and have boxed them into a tiny coastal territory in the northeast. A 12-kilometer-long "safe zone" serves as a haven for tens of thousands of civilians trapped inside rebel territory. Dr. Thurairaja Varatharajah said six people died at a makeshift hospital inside rebel territory, and he saw four more bodies scattered among the huts of displaced people. He said 48 wounded civilians were also admitted to the hospital, which he runs out of a school. Many of the victims suffered burns from the exploding shells, Varatharajah said. It was unclear who fired the shells. Varatharajah said they appeared to have come from an area where government forces are stationed.