Some unknown miscreants blew up a tower of 132 KV Sibi-Quetta double circuit transmission line on Monday morning near Bibi Nani in the Bolan pass, a Qesco spokesman here said. He said that the tower was blown up at around 3.36 hours disrupting electricity supply. However electricity supply from 220 KV transmission line was not affected. load shedding, he said, could be made partially in some areas to make good the electricity shortage caused by the incident.