NEW DELHI, March 15 — Suspected Maoist rebels stormed a police post in the heavily forested center of India early Thursday morning, killing nearly 50 police in what was apparently the biggest attack on state law enforcement in the last several years of leftist insurgency.

There are now Maoist rebels in pockets of nearly half of India’s 28 states, according to the government. They are largely entrenched in the forest belt, which is rich in natural resources, like timber and iron ore, but home to some of the poorest communities of indigenous people. Nearly 900 people were killed in the Maoist conflict in 2005, according to the most recent available official statistics.

In central Chhattisgarh state, where the incident took place, the conflict has turned ever more nasty in the last two years with the emergence of an anti-Maoist counterinsurgency force, called the Salwa Judum. Nearly 50,000 villagers, displaced by fighting, now live in flimsy tent camps along the road, as police and the militia try to flush Maoists out of the countryside. The Salwa Judum has also sent young men and women to join state security forces as so-called special police officers. In remote rural corners of India, police forces are often understaffed.

Thursday’s incident claimed dozens of those special police officers, when rebels ambushed a police post near the town of Bijapur at around 2 a.m., using gasoline bombs and improvised explosive devices, said Rajinder K. Vij, an inspector general of police in the central Indian state of Chhattisgarh. Among the 49 killed, the Indian Home Ministry said in a statement, the vast majority were newly recruited special police officers. Another 12 were injured.