CHENNAI: A classroom fight between two students escalated into a clash between two villages near Tiruttani in Tiruvallur district on Thursday. Police pacified villagers who blocked the Chennai-Tirupati highway. Police sources said that the issue started in the classroom of a government boys higher secondary school in Tiruttani. One of the students from Dharanivaragapuram village and another student from Ponpadi village had entered into an argument which later escalated into fisticuffs. Other students had intervened and brought it to an end. However, the students exchanged blows again at the bus stop after school hours. On reaching home, the student from Ponpadi had reportedly told his parents about the incident, after which about a dozen from the village went to Dharanivaragapuram to question the other student. On seeing a group from another village marching into theirs, residents of Dharanivaragapuram flagged them leading to an altercation, police said. The verbal duel soon escalated into a clash and the two groups started hurling stones at each other. A young boy was injured in the incident. Residents of Dharanivaragapuram village staged a road roko on Chennai-Tirupati road seeking action against the Ponpadi villagers. Tiruttani police rushed to the spot and pacified the villagers.