Islamic State of Iraq and al-Sham (ISIS) militants have reduced the amount of water flowing to government-held areas in Iraq's western Anbar province, officials said Thursday, a move that highlights the use of water as a weapon of war and puts more pressure on Iraqi forces struggling to claw back ground held by the extremists. Earlier this year, ISIS reduced the flow through a lock outside the militant-held town of Fallujah, also in Anbar province. But the extremists soon reopened it after criticism from residents.