Five Indian security forces were killed in a gun battle with Maoist rebels in the forests of the eastern Chhattisgarh state, according to police.
Hundreds of police and paramilitary soldiers raided a hideout in Bijapur district after receiving intelligence that a large number of rebels were gathered there, senior police officer D M Awasthi said on Saturday.
He said at least 12 security personnel were wounded in the four-hour clash, adding that authorities were working to evacuate the wounded to hospitals.
Awasthi said the body of one rebel was also recovered.
State-run All India Radio tweeted that at least 20 security personnel were missing after the engagement.
The rebels used automatic weapons and grenades during the gun battle, Hemant Kumar Sahu, a paramilitary officer told The Associated Press.
The Maoist rebels, inspired by Chinese revolutionary leader Mao Zedong, have been fighting the Indian government for more than 40 years, in a conflict that has killed tens of thousands of people. More than 10,000 have been killed since 2000 alone, according to data from the South Asia Terrorism Portal.
The rebels claim to defend the rights of Indigenous tribes and other marginalised groups, while the government calls them India’s biggest internal security threat.
The Maoists, also known as Naxalites because their left-wing rebellion began in 1967 in the Naxalbari village of the eastern West Bengal state, have ambushed police, destroyed government offices and abducted officials.
They have also blown up train tracks, attacked prisons to free their comrades and stolen weapons from police and paramilitary warehouses to arm themselves.
Last month, a roadside bomb killed at least four policemen and wounded 14 in Narayanpur district of Chhattisgarh state as they were returning from an anti-Maoist operation.