Carrying bows and arrows, a group of tribals along with BJP MLC Dilip Kumar Jayswal reached the spot and performed puja to 'capture' the land, official sources said.
The tribals alleged that the site was 'bandobast' land given to them free of cost by the government for their livelihood and had been wrongfully acquired, the sources said.
Angry over the tribals' action, members of the minority community under leadership of RJD MLA Akhtaru Imam protested on the streets and disrupted traffic.
District authorities rushed to the site and took away the tribals, the sources said, adding, two persons have been arrested in this connection.
Vigilance in the area was tightened after the incident.
The Bihar government had recently handed over 224 acres under Chatla panchayat of Kisanganj for the proposed AMU campus.