NEW DELHI, India (AP) – Communist rebels armed with rifles, hand grenades and petrol bombs attacked a police post in the jungles of eastern India on Thursday, killing at least 49 officers, police said.

The pre-dawn attack Thursday was the latest in a series of increasingly bold assaults by the rebels, who have been fighting for more than two decades in central and eastern India’s long-impoverished hinterlands.

Equipped with rifles, hand grenades and homemade petrol bombs, the insurgents appeared to have caught the 79 officers guarding the remote post by surprise, Swarnkar said. Another 12 officers were wounded in the attack.

The post is located in the state of Chattisgarh, nearly 930 miles southeast of New Delhi.

Before fleeing with weapons stolen from the police post, the attackers scattered land mines around the area, Swarnkar said. By midday, police reinforcements had reached the post and were fanning out into the jungle to search for the attackers.

Rebel operations have become increasingly bold over the past two years – and increasingly deadly.

In March 2006, insurgents detonated land mines under four trucks carrying villagers in Chattisgarh, killing 25 people. Days later, they seized a passenger train for 12 hours in the neighboring state of Jharkhand – a well-coordinated operation that highlighted their capabilities, even if no one was killed.

Those assaults – and dozens of other attacks – have prompted Indian officials to describe the rebels, know as the Naxalites for the Naxalbari region where the movement was born, as a major internal security threat.

Prime Minister Manmohan Singh went even further in an April 2006 speech, describing the insurgents as “the single biggest internal security challenge ever faced by our country.”

More than 6,000 people – police, soldiers, and civilians – have been killed since the rebels launched their campaign from the southern Indian state of Andhra Pradesh more than two decades ago.

The rebels, who claim to be inspired by Chinese revolutionary Mao Zedong, demand land and jobs for agricultural laborers and the poor. They are mainly active in six of India’s 28 states – Andhra Pradesh, Jharkhand, Bihar, Karnataka, Orissa and Chattisgarh.