ISIS Terrorist Group News: US Investigating Allegations of Chemical Weapon Use Against Iraq

The United States is investigating allegations that the Islamic State militants used chemical weapons against Iraqi forces.

If proven true, the war could escalate, Fox reported.

Iraq said the militants used chlorine gas bombs in September, according to a White House spokesman, who added that the claims had not been confirmed yet, but the U.S. is taking the allegations seriously and is investigating.

Currentl,y the U.S. is staying away from a full on-the-ground battle against the Islamic State militants. They have used airstrikes to attack the extremists in Iraq and Syria, in what was recently named Operation Inherent Resolve, since August.

The White House has asked that countries join in the coalition against ISIS to provide their own forces and partake in the fight. Nearby Arab states, also a part of the coalition, are the most obvious options for the fight, since ISIS could physically threaten their borders.

Last year when Bashar Assad was accused of using chemical weapons on his own people, it created a tense situation with the U.S., which has since diffused when Assad agreed to turn over his stockpile of chemical weapons.

When asked if a similar more aggressive approach will come from the U.S. in a battle against ISIS, if the allegations by Iraq are true, the White House kept mum.

The use of chemical weapons is against international law, and the use of chlorine is known to be extremely dangerous -- especially mixed with other toxic substances, according to Secretary of State John Kerry.

"The IS fighters seized some quantities of chlorine after seizing control of some water purification plants or sites where chlorine was kept," said a senior official, according to Fox. "IS group has some experts who were able to manufacture chlorine shells."

ISIS militants have been able to surround the capital of Iraq, Baghdad, on three sides, and Iraqi forces are gearing up to defend the important city.

Experts say that while chlorine gas can irritate the skin and eyes, as well as burn if inhaled, it is not as dangerous as the sarin gas, or nerve gas, that Assad was allegedly using.