Protesting the Centre's alleged inaction against the 1984 riots accused, more than 200 activists of various Sikh outfits on Friday blocked rail tracks on the Ludhiana-Delhi section.
A group of protestors led by Surjit Singh, president of a Sikh group, Danga Peerat Association, squatted on the rail tracks in Ludhiana and raised slogans against the government.
As a result, the New Delhi-bound Shatabdi Express, which was scheduled to leave the city at 7 am, was detained by the railway authorities at the station.
The super fast train was later sent to the national capital via Dhuri, railway sources said. Demanding justice to the victims of the 1984 anti-Sikh riots and action against the guilty, Sikh groups have been holding protests in Punjab.
On November 3, radical Sikh groups had called for a Punjab bandh on the issue.