At least eight policemen were killed in a landmine blast suspected to have been carried out by Maoist rebels in their stronghold in eastern India, police said Thursday.

Senior police officer K.B. Singh said another five policemen were injured when their vehicle was blown up late Wednesday in Koraput region, nearly 550 kilometers (345 miles) south of Bhubaneshwar, the capital of Orissa state.

The injured have been hospitalized, Singh said Thursday.

Authorities recovered four bodies from the site and another four died in a hospital later, police said. They were young recruits being trained as police drivers, Singh said.

The insurgents, who say they are inspired by Chinese revolutionary leader Mao Zedong, have been fighting for more than three decades in central and eastern India, staging hit-and-run attacks against authorities as they demand a greater share of wealth from the area's natural resources and more jobs for farmers and the poor.

The government says the rebels are India's biggest internal security threat. They operate in 20 of India's 29 states and have thousands of fighters, according to the Home Ministry.