A group of youths today waved black flags to Congress President Sonia Gandhi and tried to stop her convoy, demanding restoration of student unions in universities and degree colleges.
The incident occurred this afternoon at Balson crossing here when Gandhi on her way from Swaraj Bhawan to KP college ground, where she was scheduled to address a public meeting.
The group, said to be comprising activists of Samajwadi Party's youth wing staged a demonstration by waiving black flags and balloons and attempted to stop Sonia's cavalcade defying police barricading.
Later, police resorted to lathicharge to disperse the agitating youths. Earlier in the day, alleging corruption in UPA government and protesting Sonia's visit, BJP workers staged a dharna at Subhash Chowk.
They were later detained by the police.