The people of Liberia are voting in a presidential run-off - the first since the end of 14 years of war. Ex-football star George Weah is facing Ellen Johnson-Sirleaf - seeking to be Africa`s first elected female leader. Some voters arrived at polling stations four hours before they opened. A UN police chief said voting had been calm. Thousands of observers are monitoring the poll, along with 15,000 United Nations peacekeepers. They say they will deal swiftly with any trouble-makers. The polls are due to close at 1800GMT and official results are expected within two weeks.