Guwahati: The GST Intelligence and Enforcement Unit, Assam , entered the fourth straight day of its search operation at M/s Maa Kamakhya Coke Industries on Sunday. Investigators have signalled that two of the firm's three proprietors could be arrested if they keep staying away from the probe despite repeated notices. Advertisment The coal trading and coke manufacturing firm operates from Beltola Tiniali and runs a manufacturing unit at Amingaon .