A senior defense official says the U.S. is beefing up its use of fighter jets around the strategic Strait of Hormuz to protect ships from Iranian seizures. The official says the U.S. is increasingly concerned about the growing ties between Iran, Russia and Syria across the Middle East. The official tells reporters the U.S. will send F-16 fighter jets to the Gulf region this weekend to augment the A-10 attack aircraft that have been patrolling there for more than a week. The move comes after Iran tried to seize two oil tankers near the Strait last week, opening fire on one of them.