Jalpaiguri, Dec. 13: The state forest department has submitted a proposal to the Centre for the erection of 10 watchtowers along the rail route in north Bengal to keep a track on the movement of elephants. After seven elephants had been mowed down by a speeding goods train at Moraghat on September 22, Union minister of state for environment and forests Jairam Ramesh had visited the spot and asked state forest officers to prepare a project to erect watchtowers along the tracks. The towers will be built along the 135km stretch between Alipurduar and Siliguri Junction. According to conservator of forests, north Bengal, V.K. Sood, of the 10 towers, four will come up in non-forest areas.