Around 200 people resorted to stone-pelting and vandalisation at Patna's Pataliputra railway station over alleged shortage of trains for students appearing for a government exam, prompting police to deploy "mild force" to contain the chaos, officials said. Officials, however, maintained that appropriate arrangements of train services were ensured for students, alleging that "anti-social elements" with ulterior motives might be behind the "ruckus" created at the station. The incident took place around 11.45 pm on Saturday when a large number of students gathered at Pataliputra railway station to go to their respective exam centres.