The bus, carrying Border Roads Organisation (BRO) personnel and their family members, was on its way from Tezpur to Bishwanath Chariali when it collided with a speeding truck coming from the opposite side killing five people on the spot at Ghoramari area under Rangapara police station.
Another person succumbed to injuries on way to the hospital while the seven critically injured have been admitted to the Kanaklata Civil Hospital here.
Senior police and civil officials went to the spot and the bodies have been sent for post-mortem.