Sources: Militant fighters seize top oil refinery

Security sources tell CNN that militant fighters believed be ISIS have now taken control of the nation's largest oil refinery.

This despite claims from the Iraqi government that military forces were using bulldozers to block the terrorists' advances.

Kerry assures Iraqis of U.S. support if they unite against militants

The latest power grab follows a move by ISIS to start imposing sharia law- an extreme interpretation of Muslim law – in the cities and towns that have fallen.

Meanwhile, the number of cities now in the hands of terrorists continues to grow.Radical Sunni militants, by the thousands, capturing at least three more towns in the western desert.

They are also in control of critical Iraqi border crossings with Syria and Jordan providing ISIS with a direct pipeline for money and weapons.

OutFront with their takes: Retired Colonel Peter Mansoor, he was the executive officer to General David Petraeus during the surge in Iraq, and Lieutenant Colonel Rick Francona. He performed a number of sensitive operations in the Middle East.