Russian official cites Islamic ‘sleeper cells’ as death toll in attacks on synagogues, churches climbs to 20 Fox NewsMixed martial arts fighter, relatives of regional official among Dagestan attackers, Russian authorities say CNNDeath Toll in Dagestan Church and Synagogue Attacks Rises, Officials Say The New York TimesDagestan Terrorist Attack Exposes Russia’s Vulnerable Underbelly The Wall Street JournalRussia’s Dagestan: Gunmen kill more than 15 policemen, several civilians The Associated Press