Police say Maoist rebels have attacked a van carrying police commandos in the insurgents' stronghold in western India and 16 officers are feared to have died.

Police officer Sharad Shelar says the rebels triggered a land mine blast in the forested Gadchiroli area in Maharashtra state as the vehicle was passing through on Wednesday.

In April last year, India's security forces killed 37 Maoist rebels in two separate gunbattles in the region.

The Maoist rebels, who claim inspiration from Chinese revolutionary leader Mao Zedong, have been fighting India's government for more than four decades, demanding land and jobs for tenant farmers and the poor. The rebels have thousands of fighters and are active in several parts of India.

They routinely attack government troops and officials.