Ten police and their driver were killed in India's central Chhattisgarh state Wednesday when their vehicle hit an improvised explosive device, an attack police blamed on Maoist rebels.

India's long-running Maoist insurgency began in the 1960s and has cost thousands of lives in the decades since, although violence has died down considerably in recent years.

Wednesday's deaths were the worst casualties for security forces in more than two years and claimed the lives of police reservists returning from a mission to investigate rebel movements in remote Dantewnda district.

No rebel group has claimed responsibility for the attack so far.

India has deployed tens of thousands of forces to battle the rebels across the insurgent-dominated region known as the "Red Corridor", which stretches across several central, southern and eastern states.

Naxal groups say they are fighting for rural people and the poor.

They are believed to be present in more than 10 states across India but are most active in remote parts of the country's interior.

Their strongholds are in areas where much of the population remains mired in poverty and lacks access to critical services.

Delhi has also pumped millions of dollars into infrastructure development in the remote areas dominated by tribal communities, and claims to have confined the armed insurgency to 53 districts in 2020, down from 96 in 2010.

Twenty-two police and paramilitaries were killed in a gun battle with the far-left guerrillas in 2021.