Raipur, (IANS) Hundreds of Maoists on Monday ambushed and massacred at least 24 CRPF personnel in Chhattisgarh's Sukma district in the bloodiest attack this year.

The Central Reserve Police Force said the deadly ambush took place at 12.30 p.m. when its 74th Battalion reached a forested area in Kala Pathar near Chintagufa.

CRPF's Deputy Inspector General M. Dinakaran said 11 bodies were first recovered and a 12th trooper succumbed to his injuries in a hospital here. A subsequent search of the area led to 12 more bodies.

A trooper who survived the horror said about 300 Maoists surprised the paramilitary personnel when they were readying for lunch.

The guerrillas, who were in hiding, opened indiscriminate fire and lobbed hand grenades too, taking the CRPF by surprise.

The CRPF personnel were helping a Road Opening Party when they came under attack.

The ambush triggered a major gun battle between the Maoists and the CRPF.

The six troopers who were wounded and have been warded in hospitals include Assistant Sub-Inspector R.P. Hembram and Constables Swaroop Kumar, Mohinder Singh, Jitendra Kumar, Sher Mohammed and Latoo Oraon.

Mohammed and Oraon were said to be out of danger.

"The injured were evacuated by helicopter," Dinakaran told IANS. "Our party was deployed for road opening to provide security to road construction activities."

Security forces have launched a major search operation.

This is the same area where a Maoist carnage in 2010 left 76 CRPF troopers dead. At least 12 CRPF men were also killed in a similar Maoist attack in Sukma early this year.

Monday's killings forced Chhattisgarh Chief Minister Raman Singh to cut short his trip to Delhi where he had gone to attend a NITI Aayog meeting and fly back to Raipur.