New Delhi, March 27 :
The cases were filed against Central Collieries Company Nagpur along with some unknown public servants and Delhi-based Prakash Industries.
The investigating agency said it was conducting raids at various places including the premises of the companies in Delhi, Nagpur, Mumbai and Chhattisgarh.
The number of cases lodged by the CBI over the coal blocks allocation has gone up to 18.
The allegation against Central Collieries Company was that it sold coal in the open market against the concept of captive allocation of coal blocks for a specified end use.
On the basis of the allegations, the first case has been registered for forgery and criminal breach of trust, the CBI said.
In the second case, the CBI alleged that Prakash Industries had misrepresented facts about the net worth of the company while applying for the coal blocks.