At least seven Central Reserve Police Force (CRPF) personnel were killed Wednesday in a blast suspected to have been triggered by Maoists in Chhattisgarh's Dantewada district, according to reports.

The explosion took place when a CRPF convoy was passing through Dantewada's Malewara area, India Today reported.

Some CRPF jawans were also injured in the attack, Asian News International said on Twitter. An improvised explosive device (IED) was reportedly used to blow up the vehicle.

"All the dead security personnel belonged to the 230 batallion of the CRPF," Dantewada SP K Kashyap said.

The toll is expected to rise. 

Chhattisgarh is known to be one of the states worst affected by Maoist insurgency in India. Several attacks on security personnel have taken place in the state in the past. 

One major Maoist attacks was in Sukma in May 2013, when a group of ultras attacked a convoy of Congress leaders. At least 27 people were killed in firing and blasts on the Jagdalpur-Sukma Highway.