"The protesters, who were demanding changes in the pattern of exam for Grade-3 teachers, assembled outside the BJP office and sat in front of the main gate because of which they were pushed from there," Police Commissioner Srinivas Rao Janga said.
Thirty protesters were detained after they pelted stones at police personnel and damaged two state roadways buses which were passing from the site, DCP South Ravi Dutt Gaur said, adding three policemen and a bus passenger received mild injuries.