Judging from this video, the Spanish have retained a Francoesque approach to dealing with the public and the concept of free assembly. The attacks on these young people appear entirely unprovoked. The police are preparing for the arrival of the Pope.
I have not found any story indicating any investigation into these officers and the response of the young people (with the exception of the first woman) appears to be fear and acquiescence in the face of the abuse.
The police also broke up a “kissing protest” of gays and lesbians just before the Pope passed by. The protesters plan to kiss in front of the Pope in defiance of the Church’s view on homosexuality.