BERLIN—Twitter has suspended the accounts of a group of exile opposition groups that call themselves the “Belarusian People’s Embassies” after they were accused of identity theft by Belarusian authorities. The people’s embassy movement sprang up after last year’s presidential election, in which long-serving strongman Alexander Lukashenko claimed a resounding victory despite a widespread belief that the vote was fraudulent. The resulting crackdown has seen hundreds thrown in prison, allegations that opposition activists were tortured, and spurred a lively exile movement in countries like Latvia, Lithuania, and Germany where many Belarusians live. The various groups, which assert that Sviatlana Tsikhanouskaya, now living in Lithuanian exile, won the election, and acknowledge her as Belarus’s legitimate President, argue that their social media accounts are in effect ’embassies’ of the Belarusian people, not Lukashenko’s state. “Even though the regime is illegitimate, we never claim to be an official embassy,” the People’s Embassy group in …