The protestors were demanding that the speed of trains passing through the Chapramari wildlife sanctuary stretch be restricted to 25 - 40 km/hr, police said.
The blockade did not much affect the train movement and was withdrawn in a hour's time, railway sources said.
Meanwhile, carcasses of six elephants were being removed from the spot, forest officials said.
At least six pachyderms were mowed down by a Guwahati-bound passenger train inside Chapramari forests, around 18 km from the Banarhat police station, last night when a herd of around 40 jumbos was crossing the railway tracks.