Protesters may wage riots.Logical formLearned from12 sentences. (Race riots) may pertain-to a city.Logical formLearned from12 sentences. (Riot police) may block a road.Logical formLearned from12 sentences. (Prison riots) may spread across a country.Logical formLearned from12 sentences. A riot may start during morning.Logical formLearned from12 sentences. A riot may pertain-to a civic-holiday.Logical formLearned from12 sentences. Fighters may refrain from riots.Logical formLearned from12 sentences. A protest may degenerate into a riot.Logical formLearned from12 sentences. Riots may be sparked by frustration.Logical formLearned from12 sentences. Police may be armed with (riot shields).Logical formLearned from12 sentences. A match may bring some riot.Logical formLearned from12 sentences. Riots may worsen.Logical formLearned from12 sentences. Dozens can be constituted-of-or-filled-with riots.Logical formLearned from12 sentences. (Food riots) may take place.Logical formLearned from12 sentences. A person can be in_charge_of (riot troopers).Logical formLearned from12 sentences.