( CNN ) -- Military leaders and a group of political parties in Guinea-Bissau have announced the formation of a Transitional National Council after a recent coup plunged the African country into deeper chaos . The announcement came after a group of 22 mostly opposition political parties met with the military command on Sunday . The composition of the transitional council will be determined following another meeting Monday , TNC spokesman Fernando Vaz said . The president of the council will be the interim president of the country until parliamentary and presidential elections are held , Vaz said . The formation of the TNC effectively means that the Constitution will be suspended -- a scenario similar to events in 2003 , after a coup against then-President Kumba Iala . And pending approval by the group on Monday , the council `` will dissolve all institutions , including the national parliament , '' the spokesman said . Also on Monday , members of the TNC 's `` diplomatic commission '' will meet a delegation from the Economic Community of West African States ( ECOWAS ) regional bloc -- the first meeting between the junta and an international group . In a statement released Monday , ECOWAS stressed its `` zero tolerance for power obtained by unconstitutional means . '' `` The delegation will reaffirm ECOWAS ' rejection of the coup , which has been widely condemned by the international community ... and impress on the junta to restore constitutional rule immediately , '' the group said . Guinea-Bissau is a member state of ECOWAS . A chorus of world leaders have denounced last week 's coup , which occurred just before the second round of a presidential election set for April 29 . Coups and coup attempts are common in Guinea-Bissau since it won its independence from Portugal in 1974 . In the latest coup , soldiers took Acting President Raimundo Pereira and Prime Minister Carlos Gomes Jr. into custody Thursday night , sparking international condemnation . Both leaders are well and alive , said Daba Naualna , a spokesman for the army 's chief of staff . He said a group called the military command was behind the arrests , though it was unclear who its members are . Leaders of the nation 's armed forces have taken control of the nation to ensure stability , according to the spokesman . `` The ( army chief of staff ) thinks , for the sake of the country , that power can not fall into the streets and decided to have ( the military ) play its part in seeking solutions with the political class to resolve this crisis , '' he said . On Sunday , the `` military command '' announced the closure of Guinea-Bissau to all air traffic and maritime circulation from abroad as a matter `` of national security and safeguard of the territory of Guinea-Bissau . '' The African Union , the United Nations and the United States called for a return to civilian rule and demanded the release of the leaders . Foreign ministers from the Community of Portuguese-Speaking Countries -- a group which Guinea-Bissau is a member of -- have also condemned the coup . In a statement , the military command said the revolt was in response to a `` secret deal '' between the government and Angola . This `` deal '' was drawn up to allow Angolan troops in the country to attack Guinea-Bissau 's military , a communique from the group said . This group says the acting president and the prime minister signed the deal and also accuses the African Union -- whose rotating presidency is currently held by Angola -- of supporting intervention by Angolan forces . Guinea-Bissau 's history has been marked by several military coups , and these conflicts have ravaged its infrastructure and economy , leaving it among the poorest in the world . The nation 's first round of voting in a presidential election was held in March , and campaigning for the second round was about to begin . The election was prompted by the death of the incumbent Malam Bacai Sanha in January after a long illness . Residences of the prime minister and some government ministers were looted , witnesses said . Public media outlets are under the control of the army and are regularly broadcasting statements from the military , witnesses said Friday . Angola , also a former Portuguese colony , issued a statement last week saying it would unilaterally withdraw its troops . A number of Angolan troops are in the country to help reform the country 's armed forces , Angola said . Sanha had become president in September 2009 after the assassination of his predecessor . Despite his coming to power in what international observers deemed a fair and peaceful election , his tenure was marked by turmoil among the country 's military and political leadership . To date , no democratically elected president of the country has served a full , five-year term . CNN 's Kim Chakanetsa and David McKenzie and contributed to this report .
NEW : ECOWAS stresses it has `` zero tolerance '' for power obtained unconstitutionally . Spokesman : " The government of Nigeria is committed to the rule of law and will not tolerate any attempt by anyone to subvert or undermine this constitutional order. Pending approval Monday , the transitional group will dissolve the national parliament . A military spokesman says the acting president and prime minister are detained .