Translation from alasbarricadas.org:

22.30 Late Sunday evening, 22 June, 22:30:38
by Coordinator
After the concentration took place, disturbances erupted all around the city.
Still, at this point, one can see everywhere in the city, the lights from the firemen extinguishing fires. People who have tried to leave the city have been stopped by the police.

Some comrades had an argument with undercover police, when they were identified by them, and have been severely beaten up and arrested...
The city is full of undercover police that are following people around and photographing everybody. There are 68 arrested people, but throughout the day most people have been released and now there is 37 people left in custody. In this group there are 2 people with Spanish citizenship; and the comrades have told us that they have been violently beaten up. They speculate that the Greek government does not want problems with "international" people and it could be possible they could be release without charges or less charges.

Translation at timeline at alasbarricadas:
 http://www.alasbarricadas.org/modules.php?name=salonika&file=article&sid=2207&mode=nested&order=0&thold=

Enviado el Sunday, 22 June a las 22:30:38 por coordinadora
Tras la concentración se han producido disturbios por toda la ciudad. Todavia en estos momentos se ven las luces de los bomberos por todos lados apagando fuegos.

La gente que ha intentado dirigirse la ha detenido la policia. Unxs compas han tenido un altercado con policia secreta, al haber sido reconocidxs, y han sido "apalizadxs" y detenidxs.

La ciudad está llena de policia secreta que va siguiendo a la gente y fotografiandolos.

Ha habido 68 detenidxs, pero a lo largo del dia lxs han hido soltando hasta quedar 37. De estxs, los 2 del estado español; lös compañerxs nos cuentan que han sido salvajemente golpeadxs. Se cree que el gobierno griego no quiere problemas con "internacionales" y puede que lxs suelten sin cargos o con cargos menores.