A court in Guinea has sentenced former military ruler Moussa Dadis Camara to 20 years in prison for crimes against humanity. The charges stemmed from one of the worst massacres in the nation's history - the killing of more than 156 people after troops opened fire at a rally held in September 2009 to demand a return to civilian rule. Camara and seven of his military commanders were convicted, while four others were acquitted. He denied any involvement in the stadium massacre. His lawyer described the ruling as politically motivated and said they would appeal.