What's Happening In Syria? Iraq Bombs ISIS In Revenge For Baghdad Suicide Blasts Across The Border

Iraq's Prime Minister Haider al-Abadi announced Friday he had ordered the country's air force to strike positions held by the Islamic State group, also known as ISIS, in neighboring Syria for the first time ever, as Baghdad reeled from a series of deadly suicide car bombs coordinated by the militant organization.

ISIS, which took large swathes of territory in both Iraq and Syria in 2013 and 2014, has maintained a presence in both nations and has faced an array of foes including national armies, international powers and various militias working to defeat the jihadist organization. Last week, ISIS claimed responsibility for several deadly car bombings across the Iraqi capital of Baghdad that left dozens dead and many more injured.

As the Iraqi army coordinated with the U.S., Kurdish forces and Iran-backed Shiite militias to clear the last bastions of ISIS presence from Iraq's second city of Mosul, Abadi pledged he would cross borders to fight militants if necessary. The Iraqi air force reportedly struck ISIS-held positions Friday in the border towns of Husseibah in western Iraq and Boukamal in eastern Syria, miles away from one another along the Euphrates River.

"We are determined to chase terrorism that tries to kill our sons and citizens wherever it is found, so we gave orders to the air force command to strike Islamic State positions in Husseibah and Boukamal inside Syrian territory as they were responsible for recent bombings in Baghdad," Abadi said in a statement.

"The heroes of the sky executed the operation and responded to the terrorists with amazing success," he added, according to Reuters.

ISIS originated in the Sunni jihadist group known as Al Qaeda in Iraq, which waged a sectarian campaign of bombing against Shiites and U.S. forces in the wake of Washington's 2003 invasion and overthrow of President Saddam Hussein. Iraq has since struggled to contain militant influence in the country, paving the way for ISIS to take major cities. After a series of major successes on behalf of the Iraqi army and its Shiite militia allies, known as the Popular Mobilization Units, ISIS influence has been mostly limited to one region, the most strategic part of which is the city of Mosul. In October, Abadi announced a major U.S.-backed offensive to recapture the city, and Iraqi forces most recently recaptured the airport.

With Friday's airstrikes, the Iraqi air force has become the latest actor to join the multifaceted, six-year conflict in neighboring Syria that has killed hundreds of thousands and displaced millions more. The war began when massive anti-government protests transformed into armed insurgency by various rebel groups against Syrian President Bashar Assad. The West, Arab Gulf nations and Turkey have traditionally backed the rebels, while Russia, Iran and various pro-government militias have supported the Syrian army.

Haidar Sumeri, an analyst on Middle Eastern affairs on Twitter, said sources close to Syria's foreign ministry had been previously informed of Iraq's airstrikes. The Iraqi and Syrian governments reportedly coordinate regularly on their parallel campaigns against ISIS.