Police in Moldova said they foiled a plot by groups of Russia-backed actors who were trained to cause mass unrest during a Sunday protest against the country’s new pro-Western government. The head of Moldova’s police, Viorel Cernauteanu, said in a news conference that an undercover agent had infiltrated groups of “diversionists,” some Russian citizens, who allegedly were promised $10,000 to organize “mass disorder” during the protest in the capital, Chisinau. Seven people were detained, he said. Separately, police said they arrested 54 protesters, including 21 minors, who exhibited “questionable behavior” or were found to be carrying prohibited items, including at...