Vizianagaram District Superintendent of Police Bhavana Saxena told rediff.com over phone, "The incident occurred at around 12:15 pm when the train was on its way from Vijayawada city in south coastal Andhra to Rayagada town in neighbouring Orissa state."

"At Koneru railway station near Parvathipuram town, the Maoists, numbering about 10, surrounded the train and opened indiscriminate fire. Some of the RPF personnel, who were travelling by the same train, got off the train and retaliated. There was a brief exchange of fire, in which three RPF personnel, including a head constable and two constables died on the spot," the SP said.

"Three other RPF constables were injured. Some civilians also sustained minor injuries in the crossfire. Two Maoists also suffered injuries but they ran away with the other assailants. The Maoists looted cash amounting to Rs 10 lakh to Rs 15 lakh," the SP added.

The injured RPF personnel and civilians were shifted to the government hospital at Parvathipuram for treatment. According to unofficial sources, another RPF constable succumbed to injuries at the hospital, taking the toll to four. Unofficial sources also said that the amount looted was Rs 50 lakh.

Apparently, the Maoists had information that the RPF personnel were carrying huge cash with them in the train. They started disbursing the salaries and festival advances to the other RPF personnel at the railway stations all along the route.

On receipt of information, top railway and police officials rushed to the spot.  "A case has been registered by the Railway police. We have launched combing operations to apprehend the Maoists," the Superintendent of Police said.