PATNA, July 23 -- Police used tear gas shells, water canons and resorted to baton charge against a mob, comprising mostly students, to prevent them from marching to Lok Bhavan, the official residence of the governor, demanding the resignation of Union minister Dharmendra Pradhan over the NEET question paper leak. The police caned the protesters, most of them owing allegiance to AISA, the student wing of CPI(ML) Liberation at the Dak Bungalow intersection after they emerged from Gandhi Maidan in a 'Lok Bhavan march', and then near Lok Bhavan as they entered the restricted zone and moved dangerously close to vital installations. The administration ordered sealing of the assembly premises, situated a few hundred metres away. Members of both the houses, attending the monsoon session, had to exit from an alternate route. Trouble started brewing since around 11am soon after a large number of student activists, gathered at the historic Gandhi Maidan. "We seek the resignation of Pradhan for his failure to prevent NEET paper leaks. We also demand the resignation of home minister Amit Shah, on whose orders Delhi Police brutally tried to repress the Jantar Mantar agitation," alleged Paliganj MLA Sandeep Saurav, who is also a former general secretary of AISA and the JNU Students' Union. A massive traffic jam was seen at Dak Bungalow crossing, one of the busiest thoroughfares in the state capital, where police had put up barricades to thwart the onward march. The protesters allegedly pelted stones and some journalists were reportedly beaten up by unruly demonstrators. Upon reaching the Income Tax roundabout, some agitators made a small detour and went to the state BJP headquarters on Beerchand Patel Marg, where they allegedly hurled stones, damaging some vehicles. Several police personnel were also seen bleeding after the clashes with students....