Rocks can be at (riot police).Logical formLearned from36 sentences. Riots can be in cities.Logical formLearned from36 sentences. (Riot police) may clash.Logical formLearned from36 sentences. A riot can be in a country.Logical formLearned from36 sentences. Riots may continue.Logical formLearned from35 sentences. Riots may rage.Logical formLearned from35 sentences. (Riot police) may be armed with clubs.Logical formLearned from35 sentences. A line can be constituted-of-or-filled-with (riot cops).Logical formLearned from35 sentences. Riots may break_out in a capital.Logical formLearned from35 sentences. An anniversary may pertain-to a riot.Logical formLearned from35 sentences. A standoff can be with (riot police).Logical formLearned from35 sentences. A (death toll) can be from riots.Logical formLearned from35 sentences. (Riot police) may begin.Logical formLearned from35 sentences. Demonstrations may turn into riots.Logical formLearned from35 sentences. Hundreds of (riot police) may stand guard.Logical formLearned from35 sentences.