A (police officer) can be in (riot gear).Logical formLearned from14 sentences. A response can be to riots.Logical formLearned from14 sentences. Riots can be an ethnic violence.Logical formLearned from14 sentences. Troops can be with (riot shields).Logical formLearned from14 sentences. Dozens of (riot police) may stand guard.Logical formLearned from14 sentences. Contingents can be constituted-of-or-filled-with (riot police).Logical formLearned from14 sentences. Protesters may clash with (riot police).Logical formLearned from14 sentences. Riots may break_out on a month.Logical formLearned from14 sentences. Some persons may be killed in a riot.Logical formLearned from14 sentences. Police may carry (riot shields).Logical formLearned from14 sentences. (Riot police) may line streets.Logical formLearned from14 sentences. Some persons may die during riots.Logical formLearned from14 sentences. A riot can be daylong.Logical formLearned from14 sentences. Hundreds can be constituted-of-or-filled-with (riot officers).Logical formLearned from14 sentences. Citizens may stage riots.Logical formLearned from14 sentences.