Topline The U.S. and U.K. embassies in Russia have issued alerts over “imminent plans” for terrorist attacks in Moscow over the coming days, urging citizens in the capital to stay alert and avoid large crowds just hours after Russia’s security service claimed to have foiled an Islamic State plot against a Moscow synagogue. The United States embassy in Moscow warned of an imminent extremist attack. Anadolu Agency via Getty Images Key Facts In an alert posted late Thursday night, the American embassy said it was “monitoring reports that extremists have imminent plans to target large gatherings” in the Russian capital,...