Five security personnel were killed and 12 others injured on Saturday in an encounter with Naxals in a forest along the border between Bijapur and Sukma districts in Chhattisgarh, police officials said.

The body of a woman Maoist was also recovered from the encounter spot, they said.

A senior police officer claimed, prima facie, Maoists have suffered a "huge loss" in the gunfight.

"Separate joint teams of security forces, over 2,000 in number, had launched a major anti-Naxal operation from Bijapur and Sukma districts in the South Bastar forests, considered as the Maoist stronghold, on Friday night," state's Deputy Inspector General (anti-naxal operations) OP Pal said.

The personnel belonging to the Central Reserve Police Force (CRPF), its elite unit CoBRA (Commando Battalion for Resolute Action), the District Reserve Guard (DRG) and the Special Task Force (STF) were involved in the operation launched from five places - Tarrem, Usoor and Pamed (Bijapur) and Minpa and Narsapuram (Sukma), he said.

"At around 12 noon on Saturday, an encounter broke out between the patrolling team that was dispatched from Tarrem and ultras belonging PLGA (Peoples' Liberation Guerilla Army) battalion of Maoists near Jonaguda village under Jagargunda police station area (in Sukma)," Pal said, adding the gunfight lasted for about three hours.

As per the information received so far, five security personnel have been killed and 12 others injured, he said.

"Of the martyred personnel, one belonged to the CoBRA unit and two each are from the DRG and the 'Bastariya' battalion of the CRPF," the DIG said.

He said a woman naxal was also gunned down in the encounter.

Citing the "ground report", Pal claimed that Maoists have suffered a huge loss in the gunfight.

"Reinforcements were rushed to the spot and the operation was underway to evacuate injured jawans as well as the bodies from the forest through helicopters," he said.

State's Director General of Police DM Awasthi, Task Force Commander of IAF's Anti-Naxal Task Force (ANTF) and senior police officials monitored the rescue operation and the situation from the 'ops room' at the police headquarter, he said.

On March 23, five DRG personnel were killed when Naxals blew up a bus carrying security personnel with an IED in Narayanpur district.