Suspected Maoist rebels on Saturday attacked a convoy of cars carrying local leaders and supporters of India's ruling Congress party in a Maoist-infested area in eastern India, killing at least two party members and wounding and kidnapping several others.

Senior police officer M. Gupta said suspected insurgents triggered a land mine blast and fired at the vehicles in the Sukma area, about 215 miles (345 kilometers) south of Raipur, the capital of Chhattisgarh state.

Congress party president Sonia Gandhi said two state party leaders died in what she described as a "dastardly attack" on India's democratic system.

Police identified one of those killed as Mahendra Karma, a Congress leader in Chhattisgarh state who founded a local militia, the Salwa Judum, to combat the Maoist rebels. The anti-rebel militia had to be reined in after it was accused of atrocities against tribals — indigenous people at the bottom of India's rigid social ladder.

The wounded Congress party members, among them Vidya Charan Shukla, a former federal minister, were taken to a local hospital, police said.

The Press Trust of India news agency said the suspected rebels also took away a local party leader, Nand Kumar Patel, and his son.

PTI said the attackers blocked the road by felling trees and triggered a land mine blast that blew up one of the cars in the convoy. The attackers fired at the Congress party leaders and their supporters and then fled.

The Congress party is the main opposition party in the state.

The rebels, known as Naxalites, have been fighting the central government for more than four decades, demanding land and jobs for tenant farmers and the poor. They take their name from the West Bengal village of Naxalbari where the movement began in 1967. The fighters were inspired by Chinese Communist revolutionary leader Mao Zedong and have drawn support from displaced tribal populations opposed to corporate exploitation and official corruption.

Prime Minister Manmohan Singh has called the rebels India's biggest internal security threat. They are now present in 20 of India's 28 states and have thousands of fighters, according to the Home Ministry.