India, Sept. 13 -- Iraq's Government was racing on Saturday to contain the fallout after local Iran-backed militias were accused of attacking and shuttering a key Saudi pipeline.

Though an umbrella group of Iran-backed militias in Iraq denied their involvement, Iraq's Government confirmed the attacks had originated from its territory. The Government pledged to investigate and dismissed a military commander. The country is under mounting pressure to prevent local militias from aiding other Iran proxy groups across the region. The Iraqi Government has set a Sept. 30 deadline for nonstate groups to disarm, but several of the most powerful militias have said they will not comply.

Pressure to disarm the militias is especially acute as the Ir...