MOSCOW (Reuters) -Police detained more than 2,000 people at anti-war protests held in 48 cities across Russia on Sunday, a protest monitoring group said, as people defied the authorities to show their anger over Russia’s invasion of Ukraine. More than 5,500 people have been detained at various anti-war protests since the invasion began on Thursday, according to the OVD-Info monitor, which has documented crackdowns on Russia’s opposition for years. In Moscow, riot police often outnumbered protesters, some of whom carried hand-written placards with peace signs and anti-war slogans in Russian and…