BHUBANESWAR: India (Reuters) - Indian security forces have stepped up operations against ultra left-wing guerrillas deep in the forests of a mineral-rich central state after they killed 22 police in an ambush over the weekend, a top police officer said on Monday.

At least 30 other members of the security forces were wounded in the four-hour gun battle with Maoist rebels that took place in Chhattisgarh state on Saturday, the deadliest ambush of its kind in four years.

"The operation will be intensified," said Om Prakash Pal, deputy inspector general of police, who is leading the fight against the rebels in Chhattisgarh.

The Maoists, also known as Naxals, have waged an armed struggle against government forces for decades. They say they are fighting for the poor who have been left behind in India's economic boom.

Chhattisgarh, one of the fastest-developing states in India, has 28 varieties of major minerals, including diamonds and gold, a government website said. It also holds 16% of India's coal deposits and large reserves of iron ore and bauxite.

The Maoists, considered India's biggest internal security threat, operate in mineral-rich territory in the east and south of the country known as the "red corridor," which has shrunk in recent years because of heavy operations against them.

But last week some 400 guerrillas armed with grenades and automatic rifles attacked a police raiding party in the Bijapur district of Chattisgarh.

Pal said the rebels also suffered losses and local media reported that drone surveillance showed them taking away bodies.

"They are definitely trying to strengthen themselves but the forces put a lot of pressure on them. Now they are confined only to very few pockets. In their core area they are shrinking very fast," Pal told Reuters, adding security forces were stepping up their intelligence gathering efforts too.

WELL-ARMED 'MAOIST MENACE'

Security experts say that police forces need to be better equipped to deal with the guerrillas who are often as well-armed as the police.

In the latest encounter, the naxals carried AK-47 assault rifles, rocket launchers, and under barrel grenade launchers, said Pal.

"The government will leave no stone unturned to provide you with the best facilities," India's Home Minister Amit Shah said in a speech to security forces in Chhattisgarh on Monday.

Shah vowed to end the "Maoist menace" after paying homage to the dead security personnel and visiting a hospital to meet the injured.

"The government will not tolerate such bloodshed and a befitting response will be given. We will put an end to the ongoing battle with Maoists," Shah said.

He also held a meeting with top security officials in the state to "realign strategy" to dismantle the nexus run by Maoist leaders, a close aide to Shah told Reuters on condition of anonymity.

Uddipan Mukherjee, a joint director for government agency, the Ordnance Factory Board who has been tracking war strategy deployed by the Maoists for more than a decade said the pandemic had allowed the insurgency to recruit more members.

Others with direct knowledge agreed.

"We have intelligence reports that the Maoist leaders during the pandemic have managed to recruit hundreds of new foot soldiers, including women, living in the forests who leak details about security force patrols," a New Delhi-based bureaucrat who oversees country's internal security said.