Kenya's President Uhuru Kenyatta has been sworn in for a second term at Nairobi's Kasarani stadium. His deputy, William Ruto, has also taken his oath of office. Thousands of people are gathered at the stadium to witness the ceremony. Many Kenyans have expressed relief that the day has finally arrived. The country has been rocked by political uncertainty after two rounds of elections. The Supreme Court anulled the results of the August vote. Then opposition leader Raila Odinga boycotted the re-run polls in October. It's hoped Kenyatta will steer the country back towards stability. One of his biggest challenges will be unifying the nation.