Suspected Maoist rebels ambushed a convoy on Tuesday in a restive Indian state, killing two police officers and a journalist from the national broadcaster covering the lead up to local elections next month.

The cameraman was escorting police on a patrol in a remote stretch of Chhattisgarh, in central India, when their vehicles were attacked by armed men.

Police claimed the shooters were Maoists, also known as Naxals, who have been waging an insurgency against Indian rule in a forested belt of the country dubbed the "red corridor" for decades.

"A sub-inspector, a constable and a cameraman have been killed," Ratan Lal Dangi, a senior state police officer, told AFP.

Two others were injured in the attack.

National broadcaster Doordarshan confirmed one of its cameramen had been killed.

The state head of operations against Maoists, P. Sunder, said additional forces had been rushed to the scene.

"It is a developing situation and more forces are going to the spot. We will get more information about it once the team comes back," the senior police officer told reporters.

Last week, Maoists were blamed for blowing up a military vehicle in Bijapur district of Chhattisgarh that killed four soldiers.

Chhattisgarh goes to the polls in two phases, first on November 12 and then Nov 20.

The state has been governed by the Hindu nationalist Bharatiya Janata Party (BJP) for 15 years. The Maoists have urged voters to oust the BJP.

The rebels are believed to be present in at least 20 states across India but are most active in remote parts of Chhattisgarh, Odisha, Bihar, Jharkhand and Maharashtra.

Many regions where the Maoists are active are poor and lack access to critical services.

The guerrillas, who say they are fighting for the rights of tribal people and landless farmers, allegedly collect funds through extortion. The decades-old insurgency is believed to have cost tens of thousands of lives.

Critics say the government's attempts to end the revolt through a no-holds barred military offensive is doomed to fail.

Chhattisgarh Chief Minister Raman Singh, who is seeking a fourth term in the state polls, has blamed Maoists for impeding development projects in the state.