The United States was told last year that Saudi security forces were shooting, shelling and abusing groups of migrants, but it chose not to raise the issue publicly.
A Human Rights Watch report says the guards regularly fire on African migrants trying to enter the kingdom from Yemen and have killed hundreds in a 15-month period.
A decaying tanker holds about four times the amount of oil leaked in the 1989 Exxon Valdez disaster. Experts have warned that it is an ecological time bomb that could explode or disintegrate at any moment.