Video: Occupy protesters force White House lock-down after Washington DC march "Occupy DC" protesters demonstrating against income inequality gathered at the Capitol building in Washington DC before marching down Pennsylvania Avenue, with a brief stop at the Supreme Court before arriving at the White House. George Ogilvie, a spokesman for the US Secret Service, said the suspected smoke bomb was thrown after the majority of demonstrators had left. A small amount of smoke is believed to have been dispersed and police pushed protesters back so they could perform a thorough sweep of the area. People inside the White House were initially prevented from leaving but were later released through a side exit. President Obama and wife Michelle were not inside at the time but returned while the investigation was under way. Four people were reportedly arrested during the protests.