Kolkata, March 22 (IANS) Train movement in West Bengal's West Midnapore district was disrupted when Maoists triggered a blast Monday, the first day of their 48-hour shutdown in six states.

The shutdown has been called in Bihar, Jharkhand, Orissa, West Bengal, Chhattisgarh, Andhra Pradesh, and in three districts of Maharashtra - Bhandara, Chandrapur and Gadchiroli - in protest against the security forces' ongoing Operation Green Hunt.

The blast occurred between Midnapore and Godapiayasal stations on a branch line connecting Kharagpur and Bankura and Purulia districts of the South Eastern Railway (SER), forcing the authorities to stop the services.

'The driver of a goods train heard an explosion at Bhalukkhunia in the wee hours. He also saw some banners and flags and informed the authorities. As a precautionary measure, all movement in the line has been suspended,' SER Chief Public Relations Officer Soumitra Majumdar said.

'There has, however, been no impact on the mainline. Interstate train movement from West Bengal is normal,' Majumdar said.

The Government Railway Police and Railway Protection Force personnel conducted a foot patrol on the tracks and recovered some wires and Maoist posters.

'The bomb squad people are also there and are trying to ascertain whether there is any hidden landmine,' he said.

The Howrah-bound Purulia Express and Rupasi Bangla Express are among the trains detained at various stations.

The services will be resumed after receiving security clearance once the repair work is done.

The Maoists also felled trees to set up road blockades in some areas of West Midnapore, while vehicular movement between Midnapore and Lalgarh was halted after the discovery of a landmine at Salboni.