RAIPUR, India (AFP) - Suspected Maoist rebels killed three officials from India's ruling Congress party on Wednesday in an ambush in the central state of Chhattisgarh, police said. The rebels, who control large swathes of rural India, set off a landmine and then opened fire on a convoy of vehicles carrying party workers 170 kilometres (100 miles) east of Raipur, the state capital. "In the Maoist ambush this evening three officials from the Congress party have been killed and at least five are injured," Ramniwas, the chief of Chhattisgarh's anti-Maoist operations who only uses one name, told AFP. "Security forces from several directions have been rushed to the spot." Nand Kumar Patel, who served as Chhattisgarh chief minister from 2000-2003, was not hurt in the attack as the mine was set off shortly after his vehicle drove past it, one of the party workers in the convoy told AFP. A large vehicle was destroyed by the blast and survivors were being guarded for their own protection, police said. The convoy was returning from a meeting in Chhattisgarh, one of the states where Indian security forces are struggling to combat the decades-long Maoist insurgency.