Eleven former and current top government officials were arrested on Monday in connection with allegations of treason, sparking protests by hundreds of opposition supporters who were met by police firing tear gas, dpa reported. The 11 people arrested include former and current ministers and allegedly were connected to the plots against the government. Among those arrested is Peter Mutharika, leader of the Democratic Progressive Party (DDP) and brother of the former president. Police spokeswoman Rhoda Manjolo confirmed Mutharika's arrest, but would not comment further, saying investigations were under way. A recently established commission found that allies of former president Bingu Wa Mutharika, who died in office last year, tried to prevent then-vice president Joyce Banda from taking over the highest office, which she was entitled to under law. After several days of uncertainty she was sworn in as the country's first female president. The commission noted that Mutharika, whose party is the main opposition, might have been involved in trying to install himself as a temporary ruler of the southern African nation. When police arrived Monday to arrest Mutharika in the economic hub Blantyre and bring him to the capital Lilongwe, a journey of about 300 kilometres, his supporters took to the streets in protest. An official with the DDP who asked not to be identified told dpa that the charges were a form of "politics of retribution" being used against Mutharika by Banda. Irate supporters of the DDP, which is the main opposition, chanted anti-Banda songs while blocking Blantyre's busiest highways with tree branches to prevent the police from transporting Mutharika to Lilongwe.