Aid officials say up to three million people in Haiti have been affected by the worst earthquake in centuries

International aid efforts are under way to help the victims of the magnitude 7 quake that struck some 15 kilometers outside Haiti's capital - Port-au-Prince. It's not known how many people have been killed, but Haiti's president Rene Preval has said it's likely to be thousands. +++LMREIN+++ It's the worst earthquake to hit the country in two hundred years, and has devastated buildings across the capital. Some three million people have been affected, with tens of thousands now homeless and without clean drinking water, sanitation and food and medicine.