Persian Gulf tensions rise as U.S. warns Iran against blockade

Small craft suspected to be from the Islamic Republic of Iran Revolutionary Guard Navy (IRGCN), maneuver aggressively in close proximity of the U.S. Navy Aegis-class cruiser USS Port Royal (CG 73), Aegis-class destroyer USS Hopper (DDG 70) and frigate USS Ingraham (FFG 61) in the Persian Gulf on January 6, 2008.