The Islamic militants reportedly expanded their drive near Iraqi Kurdistan Saturday despite two U.S. airstrikes aimed at mortar positions and a seven-vehicle convoy to stop the advance on Kurdish capital of Irbil.

The Wall Street Journal reported that the militants appear to have their sights on connecting towns seized along the Kurdish-control territory. The most recent town to be seized was identified as Sheikhan.

News of the advance comes hours after U.S. warplanes launched two more rounds of airstrikes against Islamic militants in northern Iraq, taking out two mortar positions and a seven-vehicle convoy. President Obama authorized the use of force to protect U.S. personnel and Iraqi religious minorities facing a possible "genocide."

The chief spokesman for the Pentagon, Rear Adm. John Kirby, said the U.S. launched the latest airstrikes to help defend the city of Irbil, where U.S. personnel are "assisting the government of Iraq." The airstrikes were considered successful....