RWANDAN Prime Minister Pierre-Celestin Rwigema resigned from his post on Monday amid mounting accusations of financial impropriety. “Rwigema has offered his resignation in a letter addressed to President Pasteur Bizimungu,” a senior aide to Bizimungu said. Rwigema, a Hutu, became Prime Minister in October 1995 and replaced Faustin Twagiramungu — another Hutu now in exile in Belgium. An aide to Rwigema said he had been “crippled” in his work and had “met resistance” from some members of his cabinet. The resignation is the culmination of a long series of accusations against Rwigema. Last December, he narrowly survived a no-confidence vote in parliament after being accused of embezzlement and diversion of funds from a $26 million World Bank education project.