After four Class 10 girls were infected in a government higher secondary school in Tiruvannamalai town, the remaining students and staff were subjected to RT-PCR tests immediately.
Another student of the government residential school at Perunkolathur near Thandarampattur and three students of the government high school at Avur near Vettavalam were also infected.
The schools were closed for disinfection. Similarly, two teachers of a government HSS at Sathanur tested positive. A teacher who participated in a computer training course at a school at Su Valvetti was also infected.
Another teacher, who went for computer training at Ilangadu also tested positive. Sources said all four teachers were already vaccinated.