A spate of attacks on churches, synagogues and the police in Russia's Dagestan region on Sunday killed at least 20 people and injured dozens more, a regional official said on Monday. 

"As a result of the terrorist attack that took place yesterday in Makhachkala and Derbent, 46 people were injured, among them civilians and law enforcement officials," Dagestan's health minister Tatyana Belyayeva said. "Unfortunately, 20 people had been killed," she added, updating a previous toll of 19.