Six vehicles engaged in sand transportation were set ablaze near the Gangaloor area in Bijapur on Thursday, police said.IG Bastar P Sundarraj said, "Six vehicles engaged in sand transportation were set ablaze in Bijapur today. There was a dispute during the allocation of sand excavation work.""Prima facie it's suspected that discontented party might have taken the support of Naxals and torched down vehicles," Sundarraj said.