HARARE  - A Zimbabwe court convicted a group of six activists on Monday of plotting to unseat President Robert Mugabe’s government using public protests similar to ones that pushed out long-standing autocratic rulers in North Africa last year. The group, led by Munyaradzi Gwisai, a former opposition lawmaker in Prime Minister Morgan Tsvangirai’s party, was arrested in February last year after police raided a meeting they were conducting. They were charged with attempting to incite public violence to overthrow Mugabe, who has ruled the southern African state since its independence from Britain in 1980.