Suspected Maoist rebels killed 24 paramilitary commandos and wounded six on Monday in a remote part of central India in one of the deadliest attacks of a long-running internal conflict.

The soldiers were guarding road workers in the Sukma district of Chhattisgargh state, a hotbed of insurgent violence, when they came under heavy fire.

“We have recovered 23 bodies from the spot and one soldier died in Raipur during treatment,” Anand Chhabra, a senior police officer, told AFP, referring to the state capital.

He said six other commandos from the Central Reserve Police Force were critically injured and had been evacuated for treatment.

Another police officer, Sunil Tiwari, told AFP that Indian security forces were looking for “some CRPF soldiers who are missing”, adding that the rebels snatched weapons during the ambush.

Prime Minister Narendra Modi condemned the attack and offered condolences to the families of the deceased, saying the sacrifice of their loved ones would not be in vain.

“Attack on @CRPFIndia personnel in Chhattisgarh is cowardly and deplorable. We are monitoring the situation closely,” Modi posted on Twitter.

Fatal attacks by insurgents on security forces in central and eastern India are frequent, but Monday's assault was among the deadliest in years.

Television footage showed injured commandos in their army fatigues being stretchered from ambulances into hospitals for treatment.

One soldier who survived the attack, Sher Mohammed, told reporters from his hospital bed that “almost 300 of them attacked us”.

More precaution needed

State chief minister Raman Singh said Sukma, where Monday's attack occurred, was a stronghold for Maoists waging a guerilla war from their jungle bases.

The Maoists opposed efforts to build new roads and infrastructure in the remote area because it undermined their long-running campaign against India's security forces, he added.

“In future we will need to take more precautions,” said Singh, who called an emergency meeting and rushed back from New Delhi after the attack.

The Maoist insurgency started as a peasant uprising in 1967, and since then has cost thousands of lives in the rebel-dominated “red corridor” stretching through central and eastern India.

Tit-for-tat jungle skirmishes often result in heavy casualties on both sides.

Last month 11 paramilitary policemen were killed when their convoy was ambushed in Chhattisgarh, while at least 20 troops died in a separate attack in 2015.

In 2010 Maoists killed 76 police in the worst-ever massacre of security forces by the insurgents. The incident shook the country and led to pressure on the government to rethink its tactics.

Critics believe attempts to end the revolt through tough security offensives are doomed to fail, saying the real solution is better governance and development of the region.

The guerrillas, who say they are fighting for the rights of tribal people and landless farmers, often collect funds through extortion.

Modi had been seeking to stem the insurgency by earmarking development funds for revolt-hit areas and improving policing.

In 2015 he urged Maoists to put down their guns and take up ploughs, saying “violence has no future”.