Protesters squatted on tracks in several places outside Delhi, stopping trains, including the Dehradun Express and the Ranchi Rajdhani, to enforce an all India shutdown against the dilution of the SC\/ST Act, officials said today. Services were disrupted when a mob arrived at the Ghaziabad yard around 10 am today, Northern Railway officials said. Many trains, such as Saptakranti Express, Utkal Express and the Bhubaneswar and Ranchi Rajdhani as well as the Kanpur Shatabdi, were stopped ahead of Ghaziabad in Meerut and Modinagar, officials said. A mob of about 2,000 people disrupted trains at the Hapur station as well, disrupting the movement of many goods trains, they added. Delhi Police and Railway Protection Force personnel have been working to get people off the tracks. In some areas, operations have been restored, the officials said. Several Dalit organisations have called for a 'Bharat bandh' today to express their concerns over the "dilution" of the Scheduled Castes and the Scheduled Tribes (Prevention of Atrocities) Act. The Supreme Court on March 20 diluted the provisions of the Act and said government servants should not be arrested without prior sanction and private citizens, too, should be arrested only after an inquiry under the law. Dalit organisations, including the Dalit Shoshan Mukti Manch, and some political parties fear the dilution of the provisions might lead to increase in violence against Dalits.