Police have arrested more than 60 people participating in the pre-St. Patrick's Day "Blarney Blowout" around the University of Massachusetts' flagship campus in Amherst.

Amherst police said early today that 68 people have been arrested and four officers suffered minor injuries as they worked to disperse thousands of unruly students in several large crowds throughout yesterday and overnight.

Police had to use pepper spray to disperse a crowd of students outside an off-campus apartment complex who were throwing beer cans and bottles at police.

A spokesman for UMass says that students arrested will have details of their behaviour reviewed under the school's code of conduct. Sanctions can include suspension or expulsion.

Most have been charged with failing to disperse and disorderly conduct.