DAKAR (Reuters) - West Africa's ECOWAS regional bloc on Saturday extended a security force in Guinea-Bissau into 2016 to help protect state institutions amid a political crisis that has left the country without a government.Senegal President Macky Sall, who heads the Economic Community Of West African States (ECOWAS), called the extraordinary summit to discuss a political crisis in coup-prone Guinea-Bissau sparked when President Jose Mario Vaz dismissed the prime minister a month ago.He later replaced him with a new premier but a Supreme Court ruling this week deemed the new appointment unconstitutional and cabinet was dissolved."Given the fragility of the political situation in the country, the conference decided to extend the mandate of ECOMIB for six months from January to June 2016," ECOWAS said in a statement, referring to its 600-strong force. Mediation efforts by the bloc will continue, it added.The former Portuguese colony has suffered nine coups or attempted coups since 1980. But after a peaceful election in 2014, former prime minister Domingos Simoes Pereira helped convince donors to pledge over 1 billion euros ($1.13 billion)in financial assistance to the poor cashew exporter."The new prospects opened by the March 2015 (donors') conference are seriously threatened by the crisis," Kadr Dsir Ouedraogo, president of the ECOWAS commission, told reporters at the summit, which was attended by 8 heads of state including Guinea Bissau's Vaz.October presidential elections scheduled in Guinea, Burkina Faso and Ivory Coast were also discussed and ECOWAS underscored the need for free, credible, transparent and peaceful polls.(Reporting by Emma Farge and Diadie Ba; Editing by Diane Craft)Join the conversation about this story Click here to read full news..