The Jhargram train attack that killed 68 people, exposing the vulnerability of railway properties, is the latest of the over 65 Maoist attacks in the past one year.

Left-wing extremists have carried out four attacks on railway properties this month alone.

On May 19, they triggered a landmine blast on railway tracks near Jhargram in West Midnapore district, injuring two drivers of a goods train and leaving the engine partially damaged.

The next day, 14 oil tankers of a goods train derailed and caught fire after Naxals blew up railway lines between Dighwara and Pipra stations in Bihar.

Two days later, two persons, including a policeman, travelling in the Tatanagar-bound Steel Express, were injured in crossfire between Naxals and joint forces at Banstala station in West Midnapore.

Last month, Railway Minister Mamata Banerjee told Parliament that incidents of attacks by Naxals have nearly doubled to 58 in 2009 from 30 in the previous year. In 2007, 56 such attacks were reported.

She admitted that because of such attacks Railways has lost about Rs 500 crore.

"Railways has become a target of Naxals. We have lost Rs 500 crore because of Naxal bandhs and obstructions," she had said.

During the period of Naxal attacks, bandhs and rail roko, train running has usually been badly affected. Attacks on trains happen mainly in Andhra Pradesh, Bihar, Jharkhand, West Bengal, Orissa and Chhattisgarh, Banerjee had said.

According to officials, over 20 attacks alone were reported in East Central Railway, the zone which witnessed an attack on Delhi-bound Bhubaneswar Rajdhani express on March 22.

Ten boggies of the train between Gaya and Mughalsarai in Bihar were derailed after Maoists blasted rail tracks.

Concerned over the alarming regularity with which Maoist-led attacks were taking place, Railways even suggested to stop train movement during night time in the Central Indian Coalfield areas (mostly the mineral rich places in states like Jharkhand, Orissa and Chhattishgarh) -- a proposal which is being revisited today after the attack on Jnaneshwari express.

These stretches have been prone to increased Naxal activities for several months now, prompting Railways to run pilot engines ahead of Rajdhani express trains.

Each day, as many as eight Rajdhani trains pass through this stretch, an important section of the Delhi-Howrah trunk route, officials said.