New Delhi ( CNN ) -- A senior official from India 's governing Congress party suffered brutal treatment at the hands of Maoist insurgents during an audacious and deadly attack on a political motorcade over the weekend , police said Monday . The assault Saturday by hundreds guerrillas on the convoy of Congress politicians in a forested area of the eastern state of Chhattisgarh killed at least 24 people and wounded 33 , according to authorities . Among the dead was Mahendra Karma , a top local party leader and the founder of a controversial anti-Maoist militia named Salwa Judam , or the Purification Hunt . His stance against the insurgents appears to have prompted them to take a vicious approach when they captured him . They fired 30 to 40 bullets into Karma 's body and smashed his head with the butt of their guns after killing him , said Ram Niwas , the state police chief . `` He was beaten brutally even after his death , '' he said . Niwas said as many as 500 insurgents had participated in the attack . Police had previously estimated that around 200 attackers had raided the convoy . At least 16 cars in the motorcade of local Congress leaders were passing through the area when the insurgents set off a land mine and opened fire on them , police said . Among the dead were eight policemen , three laborers and some car drivers . Searching for suspects . Authorities have n't reported any arrests so far , but investigations are under way . Security forces are combing the area where the raid took place , Niwas said Monday . A judicial inquiry has been ordered into Saturday 's assault . If any failings on the part of the police are found , `` appropriate action will be taken , '' Niwas said when asked about his response to criticism of security in the area . On Sunday , Indian Prime Minister Manmohan Singh visited a hospital in Raipur , the capital of Chhattisgarh , where some of those wounded in the attack were being treated . He was accompanied by the Congress party chief , Sonia Gandhi . `` We will pursue the perpetrators of this crime with urgency , and I can assure the nation that the government is committed to bringing them to justice , '' Singh said . India 's internal threat . Saturday 's severe attack came barely three days after Singh announced what he called a significant decline in killings by left-wing insurgents , whom the federal government describes as the nation 's gravest internal security threat . `` The quantum of violence as well as the resultant killings perpetrated by the left-wing extremist groups in 2012 declined significantly for the second successive year , '' said a report Singh released on Wednesday to mark the fourth anniversary of his second term in office . He insisted his government has continued to provide public infrastructure and services in tribal districts hit by Maoist extremism . The rebels , officials say , aim to seize power through an armed struggle . Since the 1960s , the militants have said they are fighting for the dispossessed . Authorities suspect that the Maoists enjoy support not only in the poorest areas and in tribal communities but also among young people and intellectuals . In addition to targeting police , alleged police informers and people they call `` class enemies , '' the insurgents also are believed to have attacked infrastructure such as roads , bridges , railways , and power and telecommunication networks .
Most people in the convoy attacked by Maoists were from India 's Congress party . Among the 24 people killed is the founder of an anti-Maoist militia . The insurgents smashed his head with the butt of their guns , police say . Prime Minister Manmohan Singh visits the wounded , vows to find culprits .