RAIPUR, India (AFP) - India's chief anti-terrorism agency is investigating a Maoist rebel attack that killed 24 people including top local politicians in the insurgents' deadliest strike for three years, officials said on Monday.
A team from the National Investigation Agency (NIA) has arrived at the scene of Saturday's bloody ambush in the central state of Chhattisgarh, where a hunt for the Maoists is under way, officials said.
"I have asked the NIA to launch a probe. The buck has to stop somewhere," junior home minister R.P.N Singh told reporters.
Hundreds of heavily-armed rebels ambushed a convoy carrying local leaders of India's governing Congress party as it travelled through the forested Sukma area, about 345 kilometres from the state capital Raipur.
They detonated a landmine before opening fire on the convoy, spraying 25 cars with bullets, then dragged people out and killed them, police said.
Among those killed were state Congress chief Nand Kumar Patel, his son Dinesh, and former state home minister Mahendra Karma - who had set up a controversial anti-Maoist militia group in 2005.
Congress chief Sonia Gandhi, who rushed to Raipur along with Prime Minister Manmohan Singh after the ambush, condemned what she called a "cowardly act." The attack was the most brazen since 2010, when a rebel assault killed 76 police. It is the latest in a decades-long conflict that pits the insurgents against authorities in the forests of mainly central and eastern India.
Maoist rebels, who have been described by Dr Singh as the country's most serious internal security threat, are demanding land and jobs for the poor.
Security forces have launched a major search for the guerrillas in the thickly forested region, said a senior police official.
"Commandos and a large number of security forces have began the operation against the Maoists," said Mr Rajinder Kumar Vij, who heads the anti-Maoist operation in Chhattisgarh.
A NIA official said on condition of anonymity that the rebels took advantage of lower than normal levels of security for the convoy.
"We will investigate every aspect of the latest attack. The rebels used sophisticated weapons in the attack to target politicians. Their security was not handled seriously by the local cops," the official told AFP.
Mr Vishwaranjan, a retired police chief of Chhattisgarh, described the latest attack as "a clear result of intelligence failure".
The targeted convoy had been returning from a political rally in the area. Security forces should have been extra-vigilant against the possibility of an attack given that Maoists openly oppose such organised political events, he said.
"The Maoists are against any political or development activity pursued by the government in the region," said Mr Vishwaranjan, who uses one name.
According to the government, the rebels number between 8,000 to 12,000 hardcore fighters who have laid land-mines in the mineral-rich state and resist mining activity potentially worth billions of dollars.
The Maoists, who have been fighting since 1967, want to establish a communist society by overthrowing what they call India's "semi-colonial, semi-feudal" form of rule.
The revolt is believed to have cost tens of thousands of lives.
In 2009, government forces launched a huge anti-Maoist offensive known as "Operation Green Hunt", but the often poorly-trained police have had to contend with a deadly series of attacks.
Critics believe attempts to end the revolt through security offensives are doomed to fail, saying the real solution is better governance and development.