South Sudan is starting celebrations as the newest nation, while world leaders gathered in the country's capital of Juba. South Sudan's independence brought joy in the streets of the capital and marks a historical day for South Sudanese people, said Sudan's information minister, Barnaba Benjamin. Speakers at the celebrations are United Nations Secretary General Ban Ki-Moon, President of African Union, First Vice President Salva Kiir Mayardit and Sudanese President Omar Al-Bashir, who will raise the new flag. South Sudan broke away after two civil wars over five decades that cost the lives of millions. It won its independence in a January referendum -- the climax of a 2005 peace deal that ended decades of civil war with the north. Thousands packed the streets of Juba and crammed into the back of trucks, setting off fireworks, banging on plastic cans and dancing.