The youths claimed to belong to National Student's Union of India (NSUI), but the NSUI has denied any link with the incident.
"Some members of NSUI tried to enter the stage where Anna Hazare was sitting, but were stopped by volunteers. They were raising anti-Anna slogans," a member of Team Anna told IANS.
The Team Anna member claimed there were around 50 youths, while some eye-witnesses said there were around 20 people.
The youths were chanting slogans against activist Anna Hazare and Arvind Kejriwal, while hailing the NSUI, said the member.
The NSUI, which is the students wing of the Congress, however, denied its members were in any way involved in any such activity.
"Delhi NSUI has no involvement in this incident. This is a baseless allegation," NSUI Delhi in-charge Mohit Sharma told IANS.
"If any of our members are found to be involved in it, we will take disciplinary action," he added.
Team Anna Wednesday started an indefinite fast at Jantar Mantar against corruption and in support of a stringent Jan Lokpal bill.
Anna Hazare is not fasting this time because of poor health but has said he will start his fast from July 29 "if the government fails to take immediate steps to check corruption in high places".