TUMKUR: Tension prevailed at a private high school in C.N. Halli of Tumkur district on Wednesday after a teacher allegedly attempted suicide by stabbing herself with a knife. The police said an altercation broke out between Rajalakshmi, Hindi teacher at Gnanapeeth High School, and headmaster Govindaraju, who did not grant her casual leave. Subsequently, Ms. Rajalakshmi allegedly stabbed herself in the abdomen. She had been admitted in the General Hospital here, the police said.