According to details, the accident occurred near Bella cross where the bus caught fire soon after smashing into the truck.
At least 16 people sustained severe wounds among whom four are in critical condition.
Deputy Commissioner of Lasbela, Shabbir Mengal told that fire erupted in the bus has been extinguished.
The bus carrying 29 passengers was on its way to Panjgur from Karachi.
Sources say that the bus caught fire due to Iranian diesel in secret compartments.