Liberian police are reported to have stormed the headquarters of the presidential challenger Winston Tubman, but were pushed back by UN peacekeepers. <br /><br />Earlier, at least three people died in the capital Monrovia after riot police tried to break up a crowd of opposition supporters.<br /><br />There were conflicting reports as to how the violence had started. The opposition CDC party is boycotting Tuesday's presidential run-off election.<br /><br />Al Jazeera's Yvonne Ndege is in Monrovia.
