Raipur, June 2 (IANS) Six policemen and 19 prisoners were injured Saturday when a blast triggered by Maoists ripped through their vehicle in the insurgency-hit Bastar region of Chhattisgarh, police said.

All the 25 people seated in the vehicle sustained serious injuries but the condition of four policemen and 11 prisoners is critical, Additional Director General of Police (Maoist Operations) Ram Niwas told IANS.

The attack took place on a bridge on National Highway No.30 in the newly-formed Kondagaon district, some 210 km south from state capital Raipur.

The blast ripped through the vehicle carrying 25 people, including 19 prisoners, who were returning to Bastar district headquarters Jagdalpur from Kondagaon after being presented in a local court, police here said.

Niwas said it was a powerful blast and all 25 people seated in the vehicle sustained serious injuries but the condition of four policemen and six inmates was critical.

The local police authorities, which admitted that the attack was a fallout of serious security lapse, have sent an urgent message to the state home department here to rush a chopper to ferry the injured policemen and inmates to Raipur for advanced medical attention.

A police official in Jagdalpur said the attack may be a case of mistaken identity as the jail vehicle looked similar to the vehicle used by police and paramilitary forces in the Bastar region.