NEW : Amnesty International calls arrests persecution . The group says the government has been using "excessive force" against protesters and that it is investigating reports of torture by security forces. Demonstrators have been upset over pace of judicial system . Saudi official makes reference to `` deviant groups ''
NEW : Amnesty International calls arrests persecution . Dozens protest in city . Demonstrators have been upset over pace of judicial system . Saudi official makes reference to `` deviant groups ''