Dozens of riot police marched into Harvard Square again last night just before the Summerthing concert in the Stadium ended. Traffic was not allowed to enter the Square.
A little over an hour later, the bulk of the crowds had left the Square, and the riot-clad police marched out, taking their dogs and tear-gas guns with them.
Dozens of shirt-sleeved police with clubs remained behind, in the usual heavy post-concert presence.
Anonymous leaflets calling for trashing had reportedly been circulated during the day.
Lamont Library closed early.