COIMBATORE: A 17-year-old boy studying in Class 12 was arrested in Coimbatore on Monday for attacking a youth with a knife as he intervened to stop the fight with his brother. Police said the accused challenged a 16-year-old boy, studying in Class 11 in Maruthamalai Subramaniya Swamy Devasthanam Hr Sec School in Vadavalli, a few days ago for a one to one fight, blaming him for the school issuing him a transfer certificate two years ago. The 16-year-old boy accepted it and they fought in the presence of their friends behind the school premises. Meanwhile, his brother, aged 21, studying third year in college, rushed to the spot and tried to pacify them both. When the youth tried to take away his brother, the Class 12 student took out a knife and attacked him. The college student fainted on the spot and bled profusely. He was rushed to a hospital. Based on a complaint, the Vadavalli police registered a case and arrested the 17-year-old boy. He was produced in court and lodged in an Observation Home in Coimbatore. A search is on for two more boys, who accompanied him.