Two leaders from India's ruling Congress party were among 17 people killed in an attack by suspected Maoist rebels on Saturday, dpa cited news reports as saying. A group of armed insurgents attacked a political rally organized by the Congress party in the Sukma district of central Chhattisgarh state, broadcaster NDTV reported. Police said a convoy of cars carrying top Congress leaders from the state were targeted in a land mine blast, followed by heavy gun fire. The Congress party rules India at the federal level but is in the opposition in the state. Senior Congress leader Mahendra Karma, who founded a local counter-insurgency movement called Salva Judum, was killed along with former local legislator Uday Mudaliar. Party workers and local residents were among the victims, NDTV reported, citing government sources. Twenty people, including police, were also injured. A meeting to discuss the incident was held at Prime Minister Manmohan Singh's residence late Saturday and was attended by top Congress leaders. Congress President Sonia Gandhi condemned the violence, describing it as an "attack on democratic values." The area where the killings occurred is a Maoist stronghold and has witnessed several rebel attacks on police and officials in recent years.