The security forces were attacked when returning from a search operation near a forest in Chhattisgarh, a police official has said, adding that search operations are still underway for personnel missing.
Twenty-two Indian security forces have been killed and 30 others injured in a gun battle with Maoist rebels in a central Indian state, according to police, in the deadliest ambush of its kind in four years.
The forces were ambushed on Saturday while returning from a search operation near a forest in Bijapur district in Chhattisgarh, a Maoist rebel stronghold, the state police's Additional Director General Ashok Juneja said on Sunday.
"So far it is confirmed that 22 security personnel were killed," Juneja said.
"The search operation is still underway and the exact figure will be known...late Sunday evening."
The injured personnel were admitted to two government-run hospitals in Bijapur and Chhattisgarh's capital city Raipur.
More than a dozen others remained missing, he said, adding that an unknown number of Maoists were also killed in the encounter.
Juneja said the rebels looted weapons, ammunition, uniforms and shoes from the security forces who were killed.
Security personnel from the Central Reserve Police Force's elite CoBRA unit, the District Reserve Guard and the Special Task Force were attacked during the operation, said Om Prakash Pal, a senior police official.
READ MORE: Maoist rebels gun down 17 Indian police
Prime Minister Narendra Modi tweeted that the "sacrifices of the brave martyrs will never be forgotten", while Home Minister Amit Shah wrote on Twitter that India would "continue our fight against these enemies of peace & progress".
Chhattisgarh Chief Minister Bhupesh Baghel wrote on Facebook that Shah had assured him of "all the necessary help" from the national government against the militants.
My condolences to the families of the martyrs who sacrificed their lives in combat in Chhattisgarh.— Rahul Gandhi (@RahulGandhi) April 4, 2021
Decisive action needs to be taken to locate & rescue the missing Jawans.
I appeal to the State Govt to ensure best care for a speedy recovery of the injured.
The toll was the worst for Indian security forces battling the far-left guerillas since 2017, when 25 police commandos were killed in an attack.
Seventeen police from a commando patrol were killed in an attack by more than 300 armed rebels in Chhattisgarh in March last year.
Sixteen commandos were also killed in the western state of Maharashtra in the lead-up to India's election in 2019, in a bomb attack that was blamed on the Maoists.
The Maoists, also known as Naxals, have waged an armed insurgency against the government for decades. Leaders of the hardline leftist militant group say they are fighting on behalf of the poorest, who have not benefited from a long economic boom in Asia's third-largest economy.