Four persons, including two special police officers, were killed on the spot and four others seriously injured in a landmine blast triggered by Naxalites in Dantewada district early on Thursday.

The blast occurred between Gorgunda and Korampalli villages as the police party was returning to Dornapal police station on foot after being deployed for an anti-Naxal rally two days ago.

Among the deceased, two were yet to be identified, Bastar range Inspector General R K Vij said.

The injured, including three SPOs and a constable of Mizoram Armed Police, were brought to Dornapal and would be shifted by helicopter to Raipur Medical College, Vij added.

Tribal youths were recruited as SPOs on a monthly honorarium of Rs 2,000 to assist the security forces, including Central Reserve Police Force, Special Armed Force and police personnel from Mizoram and Nagaland, in the anti-Naxal operations in Bastar region, where Communist Party of India-Maoists have been active for over two decades.