Demanding immediate roll back, the protesters blocked traffic at many district headquarters and burnt effigy of Prime Minister Narendra Modi in Varanasi. Modi is an MP from the city.
At some places, the ruling party workers also disrupted rail traffic. SP leaders said the party would intensify its the agitation in coming days.
Sources said the SP, which received a drubbing at the hands of the Bharatiya Janata Party (BJP) in the Lok Sabha polls, was now ready with a massive agitation plan on issues concerning the common man. The rail fares hike has given it an opportunity.
"The BJP had shown people dreams of good days but the start is for all to see," said Rajendra Chowdhary, state spokesman of the SP.
The central government Friday raised the railway passenger fares by 14.2 percent in all classes and freight charges by 6.5 percent. The new passenger fares and freight rates will come into effect from June 25.