Maoist rebels have ambushed and killed seven policemen in an insurgency-wracked central Indian state, police say.

Senior police officer R K Vij said the fighters struck on Friday while the police were on their way to provide security to workers building a road in Dantewada district of Chhattisgarh state.

The incident took place almost 265km (165 miles) south of Raipur, the state capital.

Vij said two police officers were injured in the attack.

The region is a stronghold of the rebels, who are demanding land and jobs for the poor and often target government forces.

Inspired by Chinese revolutionary leader Mao Zedong, the rebels have been fighting the government for more than four decades.

The Indian Home Ministry says the fighters are now present in 20 of India's 28 states.

Source: Agencies