RAIPUR, India : Maoist insurgents ambushed a security patrol and killed four troopers in central India on Wednesday, police said, the latest bloodshed in a lengthy conflict over land, jobs and power.  The rebels triggered a small bomb and then opened fire on a patrol in a district of Chhattisgarh state long considered a Maoist stronghold, a senior district police officer said.

Rebels stole weapons from the Central Reserve Police Force officers killed in the attack, which occurred in a forested area of Bijapur district, 485 kilometres (300 miles) from the state capital Raipur.

“At least four security forces were killed and three injured in the ambush,” officer Sukhnandan Rathor told AFP by phone from Bijapur city. He could not confirm whether any Maoists also died in the ambush but television station NDTV said four of the attackers were also believed to have been killed.

Maoists earlier this month killed two security officials and a civilian in the state’s Sukma district.

In neighbouring Orissa state, security forces killed 14 Maoist guerrillas in September.

The Maoists have grown from a rag-tag band of ideologues into a potent insurgent force, creating a so-called “Red Corridor” that stretches throughout central and eastern India.

Prime Minister Manmohan Singh has described the Maoists as the country’s most serious internal security threat and there are frequent outbreaks of violence in areas in which the rebels are present.

Maoist rebels have for decades been fighting in the forests and rural areas for what they say are the rights of tribal people, who have some of India’s highest rates of illiteracy and poverty, and of landless farmers.

They demand land and jobs for the poor, and want to establish a communist society by toppling what they call India’s “semi-colonial, semi-feudal” form of rule. The revolt is believed to have cost tens of thousands of lives.

The Maoists are believed to be present in at least 20 states but are most active in Chhattisgarh, Orissa, Bihar, Jharkhand and Maharashtra, occupying thousands of square kilometers.

Critics believe military action is not enought to stem the revolt, saying the real solution is better governance and development.