Raipur, Oct 27(PTI): Four personnel of the Central Reserve Police Force (CRPF) were killed and two injured after Naxals blew up a mine-protected-vehicle (MPV) in poll-bound Chhattisgarh's Bijapur district Saturday, police said.

The incident occurred around 4 pm near Murdanda camp of the CRPF under Awapalli police station, when its 168th battalion was out on "area domination" operation, Bijapur Superintendent of Police Mohit Garg told PTI.

When the MPV carrying six personnel was around one km away from the camp, ultras triggered a powerful land mine blast.

"Four Central Reserve Police Force personnel (one ASI, one head-constable, two constables of 168 battalion) lost their lives in an IED blast in Awapalli Police Station area in Bijapur," P Sundar Raj, the Deputy Inspector General (Anti-Naxal Operation) told ANI.

Two injured jawans have been sent for medical treatment, he added.

Reinforcement was rushed to the spot immediately and the injured personnel were being evacuated, Garg said, adding they were retrieving the bodies from the site.

The attack took place on a day when Chief Minister Raman Singh launched the ruling BJP's campaign for the first phase of polls on November 12 in neighbouring Sukma district.

The first phase of election will cover 18 constituencies in eight Naxal-affected districts - Bastar, Kanker, Sukma, Bijapur, Dantewada, Narayanpur, Kondagaon and Rajnandgaon.

Naxals had recently put up posters in parts of Bastar region calling for boycott of the polls.