While 395 persons were arrested under Ganjam police district, 130 were nabbed under Berhampur police district in 12 days ending Sunday, Superintendent of Police (Ganjam), Ashish Singh said.
Singh, who is SP in-charge (Berhampur), said the drive would continue in both the police districts.
"We are conducting a separate inquiry into procurement of firearms by anti-socials as a number of unlicensed and country-made guns were found from them," he added.
One of the last arrests was made on Saturday when five persons were held while plotting a dacoity at Khallikote, 50 km from here.